Size (Of the dance floor) Does Matter
Without a doubt, the size of the dance floor at any event has a very significant impact on -- not only getting people to dance -- but staying there!
As I always state (as it's part of my philosophy & branding), each wedding and event is different as every person is unique. I never guarantee people are going to get up and dance. There's also nothing one person can do to guarantee people are going to get up and dance (including the cheesy, obnoxious DJ that keeps "trying" to get people who don't want to dance to do that). And, that is fine for a lot of people.
Too many people (DJ's included) think everyone has to be dancing or the wedding (or event) is a flop. That could NOT be furthest from the truth. I do NOT "force" people do to things. Like dance. If I'm out somewhere and I'm not in the mood to dance, the last thing I need is some annoying, badly-trained (if trained at all) "DJ" telling me to 'get on the dance floor.' Because inside my head I'm saying "You just need to worry about playing good music. So, shut up and leave me alone'. The thing is, I'm not alone.
People don't like being "forced" to do things. That includes dancing. A wedding -- for example -- is a celebration with family and friends of the couple who just became one. If people are dancing that's great! But, if they aren't, then just enjoy the night anyway. Do NOT let it ruin the idea of how things are or aren't going. Just because people aren't dancing does not mean they aren't having a good time.
Now, coming back to the size of your dance floor/area. The smaller the better. Here is why -- after doing this for so many years and countless events -- I believe this. Estimates on the conservative side say about 45-50% (average) of your guests will be dancing at any one time. With a variety of people and age groups, it's simply unrealistic to think EVERYONE will be up there (and many DJ's need to realize this, too. Like yesterday). Granted at the beginning of the night, the amount of people dancing might be a bit higher, but as the night goes on the crowd size decreases. So, if you have 100 guests, about 50 or so people will be dancing AT PEAK.
So, if you have a large dance floor & not many people to "fill it", it can often have an impact -- regardless of the music or any other factors. The subconscious and some psychology comes into play too.
The vast majority of people are going to be self-conscious when it comes to dancing (unless the alcohol is really flowing) as they're going to think people are looking at them while they're dancing (admit it -- you've probably thought about this in the past ;) ). So, with a large dancing area and not many dancers to fill it, the more subconscious people usually feel (admit it -- you've probably thought about this in the past. ;) ).
Now a bit of psychology in the form of you couldn't get onto the dance floor, the more likely you are to want to be there.
It's somewhat of a balancing act because an area that is too small could cause people to be feeling cramped or too hot. You want your guests feeling comfortable -- which includes dancing. When it comes to trying to helping ensure people feeling comfortable gettign up and dancing, in addition to the efforts of the DJ with the music, taking into account the space of your area for dancing can be a pretty smart move.
One of the goals at your wedding (or any event) is about having a good time and feeling comfortable (which goes hand-in-hand) and not feeling self-conscious. Whether it's 30 people or 300 people dancing!