diff --git a/client/backend.go b/client/backend.go
index bd3f79a..2774331 100644
--- a/client/backend.go
+++ b/client/backend.go
@@ -1,17 +1,25 @@
 package client
 
 import (
+	"bytes"
+	"encoding/json"
+	"errors"
 	"github.com/sqshq/sampler/metadata"
+	"io/ioutil"
 	"net/http"
 )
 
 const (
-	backendUrl             = "http://localhost:8080/api/v1"
-	registrationPath       = "/registration"
-	reportInstallationPath = "/report/installation"
-	reportCrashPath        = "repost/crash"
+	backendUrl       = "http://localhost/api/v1"
+	installationPath = "/telemetry/installation"
+	statisticsPath   = "/telemetry/statistics"
+	crashPath        = "/telemetry/crash"
+	registrationPath = "/license/registration"
+	jsonContentType  = "application/json"
 )
 
+// Backend client is used to verify license and to send telemetry reports
+// for analyses (anonymous usage data statistics and crash reports)
 type BackendClient struct {
 	client http.Client
 }
@@ -23,13 +31,57 @@ func NewBackendClient() *BackendClient {
 }
 
 func (c *BackendClient) ReportInstallation(statistics *metadata.Statistics) {
+
+	buf := new(bytes.Buffer)
+	err := json.NewEncoder(buf).Encode(statistics)
+	if err != nil {
+		c.ReportCrash(err.Error(), statistics)
+	}
+
+	_, err = http.Post(backendUrl+installationPath, jsonContentType, buf)
+	if err != nil {
+		c.ReportCrash(err.Error(), statistics)
+	}
+}
+
+func (c *BackendClient) ReportUsageStatistics(error string, statistics *metadata.Statistics) {
 	// TODO
 }
 
-func (c *BackendClient) ReportCrash() {
+func (c *BackendClient) ReportCrash(error string, statistics *metadata.Statistics) {
 	// TODO
 }
 
-func (c *BackendClient) Register(key string) {
-	// TODO
+func (c *BackendClient) RegisterLicenseKey(licenseKey string, statistics *metadata.Statistics) (*metadata.License, error) {
+
+	req := struct {
+		LicenseKey string
+		Statistics *metadata.Statistics
+	}{
+		licenseKey,
+		statistics,
+	}
+
+	buf := new(bytes.Buffer)
+	err := json.NewEncoder(buf).Encode(req)
+	if err != nil {
+		c.ReportCrash(err.Error(), statistics)
+	}
+
+	response, err := http.Post(
+		backendUrl+registrationPath, jsonContentType, buf)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if response.StatusCode != 200 {
+		body, _ := ioutil.ReadAll(response.Body)
+		return nil, errors.New(string(body))
+	}
+
+	var license metadata.License
+	json.NewDecoder(response.Body).Decode(&license)
+
+	return &license, nil
 }
diff --git a/component/statusbar.go b/component/statusbar.go
index 3175da6..c983dc5 100644
--- a/component/statusbar.go
+++ b/component/statusbar.go
@@ -19,12 +19,12 @@ type StatusBar struct {
 }
 
 func NewStatusLine(configFileName string, palette console.Palette, license *metadata.License) *StatusBar {
+
 	block := *ui.NewBlock()
 	block.Border = false
-
 	text := fmt.Sprintf(" %s %s | ", console.AppTitle, console.AppVersion)
 
-	if license == nil || !license.Purchased || !license.Valid {
+	if license == nil || !license.Valid {
 		text += console.AppLicenseWarning
 	} else if license.Username != nil {
 		text += fmt.Sprintf("%s | licensed to %s", configFileName, *license.Username)
diff --git a/config/config.go b/config/config.go
index 2470d75..01fad02 100644
--- a/config/config.go
+++ b/config/config.go
@@ -27,20 +27,18 @@ func LoadConfig() (*Config, Options) {
 	_, err := flags.Parse(&opt)
 
 	if err != nil {
-		panic(err)
+		console.Exit("")
 	}
 
 	if opt.Version == true {
-		println(console.AppVersion)
-		os.Exit(0)
+		console.Exit(console.AppVersion)
 	}
 
-	if opt.ConfigFile == nil && opt.License == nil {
-		println("Please specify config file using --config flag. Example: sampler --config example.yml")
-		os.Exit(0)
+	if opt.ConfigFile == nil && opt.LicenseKey == nil {
+		console.Exit("Please specify config file using --config flag. Example: sampler --config example.yml")
 	}
 
-	if opt.License != nil {
+	if opt.LicenseKey != nil {
 		return nil, opt
 	}
 
diff --git a/config/options.go b/config/options.go
index d04277d..14cd61b 100644
--- a/config/options.go
+++ b/config/options.go
@@ -1,8 +1,9 @@
 package config
 
 type Options struct {
-	ConfigFile  *string  `short:"c" long:"config" required:"false" description:"set path to YAML config file"`
-	License     *string  `short:"l" long:"license" required:"false" description:"provide license key. visit www.sampler.dev for details"`
-	Environment []string `short:"e" long:"env" required:"false" description:"specify name=value variable to use in script placeholder as $name. This flag takes precedence over the same name variables, specified in config yml"`
-	Version     bool     `short:"v" long:"version" required:"false" description:"print version"`
+	ConfigFile       *string  `short:"c" long:"config" required:"true" description:"Path to YAML config file"`
+	LicenseKey       *string  `short:"l" long:"license" description:"License key. Visit www.sampler.dev for details"`
+	Environment      []string `short:"e" long:"env" description:"Specify name=value variable to use in script placeholder as $name. This flag takes precedence over the same name variables, specified in config yml"`
+	Version          bool     `short:"v" long:"version" description:"Print version"`
+	DisableTelemetry bool     `long:"disable-telemetry" description:"Disable anonymous usage statistics and errors to be sent to Sampler online service for analyses"`
 }
diff --git a/console/console.go b/console/console.go
index 09c1be1..f502739 100644
--- a/console/console.go
+++ b/console/console.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	ui "github.com/gizak/termui/v3"
 	"log"
+	"os"
 	"time"
 )
 
@@ -33,10 +34,17 @@ func Init() {
 	fmt.Printf("\033]0;%s\007", AppTitle)
 
 	if err := ui.Init(); err != nil {
-		log.Fatalf("failed to initialize termui: %v", err)
+		log.Fatalf("Failed to initialize ui: %v", err)
 	}
 }
 
 func Close() {
 	ui.Close()
 }
+
+func Exit(message string) {
+	if len(message) > 0 {
+		println(message)
+	}
+	os.Exit(0)
+}
diff --git a/main.go b/main.go
index 4224d07..23110b6 100644
--- a/main.go
+++ b/main.go
@@ -21,10 +21,38 @@ import (
 )
 
 type Starter struct {
-	lout   *layout.Layout
-	player *asset.AudioPlayer
-	opt    config.Options
-	cfg    config.Config
+	player  *asset.AudioPlayer
+	lout    *layout.Layout
+	palette console.Palette
+	opt     config.Options
+	cfg     config.Config
+}
+
+func (s *Starter) startAll() {
+	for _, c := range s.cfg.RunCharts {
+		cpt := runchart.NewRunChart(c, s.palette)
+		s.start(cpt, cpt.Consumer, c.ComponentConfig, c.Items, c.Triggers)
+	}
+	for _, c := range s.cfg.SparkLines {
+		cpt := sparkline.NewSparkLine(c, s.palette)
+		s.start(cpt, cpt.Consumer, c.ComponentConfig, []config.Item{c.Item}, c.Triggers)
+	}
+	for _, c := range s.cfg.BarCharts {
+		cpt := barchart.NewBarChart(c, s.palette)
+		s.start(cpt, cpt.Consumer, c.ComponentConfig, c.Items, c.Triggers)
+	}
+	for _, c := range s.cfg.Gauges {
+		cpt := gauge.NewGauge(c, s.palette)
+		s.start(cpt, cpt.Consumer, c.ComponentConfig, []config.Item{c.Cur, c.Min, c.Max}, c.Triggers)
+	}
+	for _, c := range s.cfg.AsciiBoxes {
+		cpt := asciibox.NewAsciiBox(c, s.palette)
+		s.start(cpt, cpt.Consumer, c.ComponentConfig, []config.Item{c.Item}, c.Triggers)
+	}
+	for _, c := range s.cfg.TextBoxes {
+		cpt := textbox.NewTextBox(c, s.palette)
+		s.start(cpt, cpt.Consumer, c.ComponentConfig, []config.Item{c.Item}, c.Triggers)
+	}
 }
 
 func (s *Starter) start(drawable ui.Drawable, consumer *data.Consumer, componentConfig config.ComponentConfig, itemsConfig []config.Item, triggersConfig []config.TriggerConfig) {
@@ -39,6 +67,14 @@ func (s *Starter) start(drawable ui.Drawable, consumer *data.Consumer, component
 func main() {
 
 	cfg, opt := config.LoadConfig()
+	bc := client.NewBackendClient()
+
+	statistics := metadata.GetStatistics(cfg)
+	license := metadata.GetLicense()
+
+	if opt.LicenseKey != nil {
+		registerLicense(statistics, opt, bc)
+	}
 
 	console.Init()
 	defer console.Close()
@@ -46,58 +82,35 @@ func main() {
 	player := asset.NewAudioPlayer()
 	defer player.Close()
 
-	license := metadata.GetLicense()
-	statistics := metadata.PersistStatistics(cfg)
-
-	if opt.License != nil {
-		// validate license
-		// save to storage on success
-		// exit with info
-		return
-	}
-
 	palette := console.GetPalette(*cfg.Theme)
-	lout := layout.NewLayout(component.NewStatusLine(*opt.ConfigFile, palette, license), component.NewMenu(palette), component.NewIntro(palette))
-	bc := client.NewBackendClient()
+	lout := layout.NewLayout(
+		component.NewStatusLine(*opt.ConfigFile, palette, license), component.NewMenu(palette), component.NewIntro(palette))
 
-	if license == nil {
+	if statistics.LaunchCount == 0 {
+		if !opt.DisableTelemetry {
+			go bc.ReportInstallation(statistics)
+		}
 		lout.RunIntro()
-		metadata.InitLicense()
-		bc.ReportInstallation(statistics)
-	} else if !license.Purchased /* && random */ {
-		// TODO lout.showNagWindow() with timeout and OK button
+	} else /* with random */ {
+		// TODO if license == nil lout.showNagWindow() with timeout and OK button
+		// TODO if license != nil, verify license
+		// TODO report statistics
 	}
 
-	starter := &Starter{lout, player, opt, *cfg}
-	startComponents(starter, cfg, palette)
+	metadata.PersistStatistics(cfg)
+	starter := &Starter{player, lout, palette, opt, *cfg}
+	starter.startAll()
 
 	handler := event.NewHandler(lout, opt)
 	handler.HandleEvents()
 }
 
-func startComponents(starter *Starter, cfg *config.Config, palette console.Palette) {
-	for _, c := range cfg.RunCharts {
-		cpt := runchart.NewRunChart(c, palette)
-		starter.start(cpt, cpt.Consumer, c.ComponentConfig, c.Items, c.Triggers)
-	}
-	for _, c := range cfg.SparkLines {
-		cpt := sparkline.NewSparkLine(c, palette)
-		starter.start(cpt, cpt.Consumer, c.ComponentConfig, []config.Item{c.Item}, c.Triggers)
-	}
-	for _, c := range cfg.BarCharts {
-		cpt := barchart.NewBarChart(c, palette)
-		starter.start(cpt, cpt.Consumer, c.ComponentConfig, c.Items, c.Triggers)
-	}
-	for _, c := range cfg.Gauges {
-		cpt := gauge.NewGauge(c, palette)
-		starter.start(cpt, cpt.Consumer, c.ComponentConfig, []config.Item{c.Cur, c.Min, c.Max}, c.Triggers)
-	}
-	for _, c := range cfg.AsciiBoxes {
-		cpt := asciibox.NewAsciiBox(c, palette)
-		starter.start(cpt, cpt.Consumer, c.ComponentConfig, []config.Item{c.Item}, c.Triggers)
-	}
-	for _, c := range cfg.TextBoxes {
-		cpt := textbox.NewTextBox(c, palette)
-		starter.start(cpt, cpt.Consumer, c.ComponentConfig, []config.Item{c.Item}, c.Triggers)
+func registerLicense(statistics *metadata.Statistics, opt config.Options, bc *client.BackendClient) {
+	lc, err := bc.RegisterLicenseKey(*opt.LicenseKey, statistics)
+	if err != nil {
+		console.Exit("License registration failed: " + err.Error())
+	} else {
+		metadata.SaveLicense(*lc)
+		console.Exit("License successfully verified, Sampler can be restarted without --license flag now. Thank you.")
 	}
 }
diff --git a/metadata/license.go b/metadata/license.go
index 06afa98..f5a67e6 100644
--- a/metadata/license.go
+++ b/metadata/license.go
@@ -6,11 +6,10 @@ import (
 )
 
 type License struct {
-	Purchased bool
-	Valid     bool
-	Key       *string
-	Username  *string
-	Company   *string
+	Key      *string `yaml:"k"`
+	Username *string `yaml:"u"`
+	Company  *string `yaml:"c"`
+	Valid    bool    `yaml:"v"`
 }
 
 const licenseFileName = "license.yml"
@@ -32,18 +31,12 @@ func GetLicense() *License {
 	}
 }
 
-func InitLicense() {
-
-	license := License{
-		Purchased: false,
-		Valid:     false,
-	}
+func SaveLicense(license License) {
 
 	file, err := yaml.Marshal(license)
 	if err != nil {
-		log.Fatalf("Failed to marshal config file: %v", err)
+		log.Fatalf("Failed to marshal license file: %v", err)
 	}
 
-	initStorage()
-	saveStorageFile(file, getPlatformStoragePath(licenseFileName))
+	saveStorageFile(file, licenseFileName)
 }
diff --git a/metadata/statistics.go b/metadata/statistics.go
index 8a417d4..d64afc4 100644
--- a/metadata/statistics.go
+++ b/metadata/statistics.go
@@ -9,6 +9,8 @@ import (
 	"runtime"
 )
 
+// Anonymous usage data, which we collect for analyses and improvements
+// User can disable it, along with crash reports, using --telemetry flag
 type Statistics struct {
 	Version         string
 	OS              string
@@ -38,7 +40,7 @@ func PersistStatistics(config *config.Config) *Statistics {
 		}
 
 		statistics.WindowWidth = w
-		statistics.WindowWidth = h
+		statistics.WindowHeight = h
 		statistics.LaunchCount += 1
 
 	} else {
@@ -50,6 +52,7 @@ func PersistStatistics(config *config.Config) *Statistics {
 			WindowHeight:    h,
 			ComponentsCount: countComponentsPerType(config),
 		}
+		initStorage()
 	}
 
 	file, err := yaml.Marshal(statistics)
@@ -62,6 +65,27 @@ func PersistStatistics(config *config.Config) *Statistics {
 	return statistics
 }
 
+func GetStatistics(cfg *config.Config) *Statistics {
+	if !fileExists(statisticsFileName) {
+		return &Statistics{
+			Version:         console.AppVersion,
+			OS:              runtime.GOOS,
+			LaunchCount:     0,
+			WindowWidth:     0,
+			WindowHeight:    0,
+			ComponentsCount: countComponentsPerType(cfg),
+		}
+	} else {
+		file := readStorageFile(getPlatformStoragePath(statisticsFileName))
+		license := new(Statistics)
+		err := yaml.Unmarshal(file, license)
+		if err != nil {
+			log.Fatalf("Failed to read statistics file: %v", err)
+		}
+		return license
+	}
+}
+
 func countComponentsPerType(config *config.Config) map[string]int {
 
 	m := make(map[string]int)
diff --git a/metadata/storage.go b/metadata/storage.go
index beb62d4..a0db7b7 100644
--- a/metadata/storage.go
+++ b/metadata/storage.go
@@ -51,6 +51,6 @@ func readStorageFile(path string) []byte {
 func saveStorageFile(file []byte, fileName string) {
 	err := ioutil.WriteFile(getPlatformStoragePath(fileName), file, os.ModePerm)
 	if err != nil {
-		log.Fatalf("Failed to save the storage file: %v", err)
+		log.Fatalf("Failed to save the storage file: %s %v", fileName, err)
 	}
 }