Contract riders have a lot more to do than with blue M&M’s. It’s usually a list of things that need to be in place that help the performer do his very best.
I think it’s a very good idea to have your own rider of sorts. You might not want to call it that, but I think it’s wise to have a list of things you want speakers to do and things you want to happen at your event – things based on history that will help the session go well, things like a speaker not talking about their books too much in their presentation or arriving at a certain time in the day. You can learn every time you book a speaker, refine that list, and implement it every time you book somebody new to increase the likelihood that your objectives are met.