My wife Stellar points out that one thing I get from posting my stuff on social media is all of the "Free Exposure" that past clients used to try to entice me with in lieu of payment. This is certainly true. It is exposure and it is free.
It is also of very limited value with respect to finding paying customers. However I have had some luck selling things as a result of posting on Facebook and Instagram, but that is due to my own efforts not the passive "exposure" that might result from doing free illustrations for a role-playing game.
I said "very limited value" but I should amend that. Facebook has garnered me more sales and contacts than any other activity I've ever tried. (outside of the sign painting business) It's not as fun as going to a gaming or sci fi convention to show my portfolio around but it's frankly more profitable. And it's free.
What I meant to emphasize is that it's not a passive activity. It requires a tremendous investment of energy time and persistence, none of which is forthcoming from the "free exposure" people who imagine that including your name in small print in the illustration credits will be equivalent to Rosie O'Donnell sharing a Tickle Me Elmo toy on prime time television.
Rosie was genuinely delighted with that toy and shared it with joy and enthusiasm. The free exposure people aren't going to do that. They are not merely indifferent to your art they are utterly contemptuous of it and of you as a person. They believe, or profess to believe, that they are doing you an enormous favor by "allowing" you to post your art in their book for free as opposed to paying you for the value that your art adds to their product.
Adding to the confusion, Instagram is rank with "Art Magazines" which are actually just an Instagram account featuring the work of various artists. Many of which the artist has to pay to be featured in, and which garner the artist absolutely nothing that he can't achieve on his own with his own Instagram account. Hundreds of thousands of dummy "followers" and dummy "likes" do nothing to boost your career.
There's no vetting for quality so your work is shown alongside any level of amateurism plus the actual replies that you get are shallow and are usually some amateur artist trying to get you to follow their Instagram in the hopes of boosting their own apparent legitimacy.
(None of this is Instagram's fault I love Instagram, but if it can be abused someone will abuse it)
In summary, exposure has enormous value, but it requires a tremendous amount of work on your part. It can in fact be "Free" as is the case with social media, meaning you should never pay money for it, but leveraging it into a paying proposition will never be passive it will take an enormous investment of time and energy.
Hey speaking of exposure, here's a girl with no clothes on.