A lot of people like Chaturbate because you can chat for free and there is a large community supporting it.
Over the years 60% of all girls are working on this site.
Sending tips is not done in dollars or euros, but in a virtual currency called tokens. A token is approximately worth 5 cents (this depends on the package you buy).
You can also use tokens on buying content on Chaturbate (like pictures & movies / clips) or to go private with models).
Things got moving really quickly because of the awesome features they had implemented.