It’s a mix of self promotion, service to potential clients, service to professional colleagues (depending on whether the questioner is a potential client or a fellow trainer) and professional collaboration.
I’ve gotten several clients from my profile here on IDEAfit, so I mainain an active presence on the forum, I keep my certification information current, and I post my events.
Of course there is some portion of self promotion in answering questions here. Sometimes when I feel the person asking might benefit from more than just a simple answer here, I even invite them to contact me if they would like. And I sometimes include a bit of information about what I can do for them or other fitness professionals looking for CECs and more. I love to teach and I hope to make a difference. The more professionals that I can help to raise their game, the more people I will indirectly reach through these fitness pros. I also enjoy reading all of the related content and the ideas of others in this forum. My daily goals are to learn something everyday, help someone everyday, to be courteous and thoughtful everyday, and to do something nice for at least one person everyday without expecting any type of reciprocation for the kindness.
Isn’t that what we are all about? But don’t forget we still have families to provide for, bills to pay, and lives to live. Unless you are already wealthy, you have to get paid something as well. If I had a financial backer who provided me the funds to live reasonably well, I would do all that I already do for free.