Samba Mobile, a U.K. startup that was offering free 3G broadband in exchange for users watching video adverts on PCs and tablets, has shut down after less than two years of operation. Samba had launc
Samba Mobile, a UK startup that gives its users free 3G mobile broadband in exchange for watching video adverts, and Whatsapp-style Spanish startup yuilop, which provides free VoIP calls and texts to