Cross-posting services, is there a ready-made code?

Question

Facebook

I began to constantly notice advertisements for new cross-posting services, in a month 6-7 pieces were opened and these are just the ones I saw. Where do so many of them come from? Is there some kind of engine for such services or is it self-written? What is the benefit of such a service in the presence of several dozen competitors?

Answer 1

Baader-Meinhof phenomenon.
In fact, 10 social networks are opened per month.

Answer 2

well, you can steal a million accounts, and this money is not small