They asked me for 0.99€ forever, but they never suspended my account. This is true of everybody I know, but I am aware that some people had to pay. I am not sure of the criteria that they used to choose those who had to pay.
I knew early adopters who had to pay end the end of their trial period. Ultimately they were not successful at charging people for social network participation because they needed everyone they could get.
In my case, WA would show me a message to the effect after some specific period, I had to pay but when that period passed, nothing happened. So in effect, I never paid anything as a android user.