I think there is a big market for people that want to pay $5-$15/mo for a small data only plan for people that will use Wifi on their phone 90% of the time but want to use mobile data just occasionally. Most of the major plans start way over that.
I see they're selling data-only SIMs for phones. Is that new? I thought Apple & Google insisted phones must have plan with a phone line. (If its good I think I'll go back to data only (with Google Voice))