For the first several years from the advent of social media, businesses could take advantage of a HUGE audience to peddle their wares and promote their offerings FOR FREE. Could it be too good to be true?!?!
In short: yes.
I would never suggest that Facebook used shady crack dealer tactics to get people hooked and then start charging. However, at some point, someone (besides venture capitalists who--surprise, surprise--actually wanted to turn a profit someday) had to start paying the salaries of the smart, hardworking people of Facebook if we all wanted to keep using it to connect with friends, family, communities and to reach wide audiences as businesses.