There were always alternatives, just carried certain other costs. SMS was a major competitor, and as its prices have declined significantly internationally, the

There were always alternatives, just carried certain other costs. SMS was a major competitor, and as its prices have declined significantly internationally, the friction with using it would as well. Being the first mover is not a infinitely defensible advantage. If another app comes along but doesn't carry the $1 a year fee, it wouldn't be hard to motivate people to switch.