During Society Day at the Federation of Genealogical Societies 2012 conference, I attended "Getting the Speaker Your Society Needs," led by Billie Stone Fogarty. Here are some of the main points I gleaned from the session:
In order to get the speakers your society wants, you have to ask the members what they want. Fogarty suggests that we gather this information several different ways such as surveys, meeting interviews or email.
Society programs should reflect members' different research needs, levels of experience, locations of interest and time frames. Do not rely on one speaker for multiple sessions throughout the year or your audience will become complacent.
Fogarty also addressed the speakers' needs from societies. She says that speakers depend on societies to promote events (though I know speakers that prefer to promote themselves. I prefer both.).
Societies must have a good venue and good equipment. Speakers do talk among each other about good and bad speaking experiences. You don't want your society to get a negative reputation.
Fogarty stresses that societies must understand all the time, money, travel and effort that goes into a genealogy presentation even before it is shared with the audience. Compensation should reflect that.
Do you want to book a nationally-known speaker for your event? Plan ahead. Way ahead. National speakers book at last a year in advance and often more.
If you're stuck for new speakers, check colleges, webinars, and the Genealogical Speakers Guild. Also consider the online lectures available at FamilySearch.