Many large conventions are set up by A/V folks who use a presenter remote system that inevitably causes more problems than it solves. The presenter is usually a big wig and the tech folks assume that the big wig can’t handle more than one button on a remote. So they use a remote that has only one large green button on it. The problem is that the remote is not hooked up to a computer. It signals a light in the A/V booth and when the tech person sees the light go on, they advance the slides. Sounds good in theory, but I have seen it far too often mess up a presenter. In the past, when presenters just put up a whole slide and talked for a few minutes about it, this system was usually OK. But today, presenters use builds on their slides and the system breaks down. The tech person is not watching the light closely enough to keep up with the presenter or gets ahead of the presenter when they think that the light flashed twice. I’ve seen this ruin keynote presentations. If you are presenting in a big venue, insist that you use your own remote hooked up to your own laptop sitting on or in front of the stage so that the signal from the remote will be clear and you will control it.