Why do we pay to present at conferences?
It costs a lot of money to put conferences on. Generally, the fees are to help cover this.
In many fields, the majority of people attending are also presenting. If they didn't charge people to present, they wouldn't be able to generate enough revenue from attendees to make it work.
Note that $50 is very cheap for an academic conference--in my experience, most cost hundreds of dollars. Even then, in many cases the conference fees don't cover the whole cost of the conference, and the difference has to be made up with sponsorship or from other sources.
I had your same reaction at my first conference. Now, I have just finished helping to organize a small conference (computer science). As @dan1111 wrote, conference really do not come for free.
These are typical items you need to cover with the registration fees:
- Room costs (if the conference is held at a conference center / hotel; credits @Andrew)
- Welcome reception
- Coffee breaks
- Lunches
- Social dinner
- Water for the speakers
- Accommodation for keynote speakers
- Printed proceedings (common to have them in CS)
- Excursions (small excursions are often included in the fees. Sometimes they are partially covered by the fees to offer a discount to the participants) including transportation
- Best paper award
Some conferences cover the registration fees to the organizers, as well (not in our case).
Also keep in mind that for small-to-medium conferences, you can never guess the number of participants with high accuracy. If you pay for 80 participants to the catering service but only 50 participants show up, you lose the money.
Finally, sometimes you just have a wrong guess and make some little profit out of the registrations. That money often goes back to the organizing university (or the societies) to hopefully cover up for other research-related expenses.
First off I would like to say: apparently my experience is not normal. From most of the answers/comments on here it seems most people pay to present at conferences. I guess I'll recognize that in fairness.
However...that has not been my experience with conferences in the computer programming field. Yes, conferences cost money to put on...which is why people attending them pay money. A person presenting is part of the conference...what the people attending are paying to see! That's like charging an actor admission to their theater performance...they are the performance!
I have not personally paid to speak at conferences.
EDIT: Many in the comments have said this is academic vs. business. I do not think this is correct. I believe it is field vs. field. In the last conference I presented at the only presenters that weren't actively in academia at that moment were myself and a representative from Adobe. In fact it was neat because it resulted in myself getting to invited to speak at some colleges...which I also did not pay to do :)
I think at this point, mixing my experiences with the experiences explained on this thread, it would seem that if you're in a field with enough people attending conferences where you can have a distinct set of "presenters" vs. "attenders" then the presenters will likely not pay. If the community in your field is small enough that getting together enough people for a conference pretty much means most of the "attenders" WILL be "presenters" then you're likely gonna have to pay your share of setting up the conference. I'm sure there's also fields in-between where you may pay a lesser rate or here it's hit-and-miss from conference to conference on whether you'll be paying to present.
In the end it seems experiences vary WIDELY on this subject.