I recall paying for it in iOS, and getting a "it's free for a year" message on Android before the Facebook transaction.
they didn't take venture capital and instead self funded. even if you aren't generating revenue, you can bootstrap
And how did they pay expenses if they had no capital and no revenue?
Bootstrapping isn't no capital, it's no outside investment. The two founders had worked for Yahoo for years before quitting, they used their savings and kept expenses low.