Is it normal for conferences to charge a registration fee from selected authors?
My answer to Is it normal for conferences to charge a registration fee from selected authors? on Quora
It depends very much on the type of conference. I believe charging speakers is quite common in academic conferences—presumably because there are plenty of niche academic conferences where almost all of the attendees are speaking or presenting a paper.
For-profit commercial conferences are usually free for speakers, and often pay them a stipend. If they won’t, it’s worth being a little suspicious—some will tell you that it’s such great exposure for the speaker to present at such a prestigious event that they don’t feel the need to provide the ticket for free, but the event had better be VERY prestigious for that to be convincing to you.