Sometimes, at a wedding, it's a great time filler while you're assembling the ladies/gents for the garter/bouquet ... you can put on some EDM, let them move to the beat as you orchestrate the event. It can be a lifesaver, so you don't loose momentum looking for a chair, or waiting for someone to get out of the bathroom. It keeps the flow going, and allows you to MC over it - there are no words to distract the audience from the music.
You can also, just prerecord a solid dance beat and keep it handy for just these occasions.