What's the deal with dancing women?

I find myself affecting a Jerry Seinfeld voice when these little social commentaries well up in me. Okay, I understand that the interwebs is kept alive by advertising. Fine. I've grown to see past the ads most of the time. Sometimes they can be pretty funny like the GMail ads. I occasionally use GMail to send gaming notes from school to home or elsewhere, a nice little delivery system there. GMail's context sensitive ads can produce a giggle on a occasion. I might write a note about a horror scene "Dead bodies rise from the grave" And Gmail puts a note saying "Buy Dead Bodies cheap!" as a note. I remember an adventure with Giant Spiders that had a bunch of Exterminator ads.
I have noticed some strange trends...
Places like Match.com and Trulove.com use pretty girls on their ads. That I can understand. If I were in the market for a new girlfriend, a site offering pretty ones would be what I was looking for. But I've noticed that Online Universities use pictures of the same women as dating sites. I can't tell right off the bat whether I am being solicited by a dating site or Phoenix university for my business. I get the idea that sex sells and that a pretty girl might catch my eye and thus I will linger over their ad, so okay, fairs fair in the ad business.
But here is the puzzler.
Lots of dubious looking mortgage and tax sites, and more and more sites lately have been using these animated gif ads of woman dancing. My first thought was, well sex sells, an animated woman might attract more attention than a still one (in some circles) so that must be it. But here is the thing, these animated women dancing ads are not generally of models or even very attractive women by societies standards. Could they not avoid a more attractive model?
So then I thought, maybe it is the motion that is meant to catch my attention. If so, well anything could work, why dancing women? Then I thought, maybe the dancing women who look 'normal' are less threatening to other women, and so you only need one ad for everyone (since coding by gender requires some work). This seems plausible. The dancing women go from happy looking, they are dancing because interest rates are lower... um okay, to only vaguely humanoid (cloaked in abstract colors and such), hey there is something vaguely human dancing on my screen, I better check this out.
When the same animated gifs appear on different product ads, I tend to give them even less (if that is possible) attention than I do when they are different. This whole thing makes me wonder if maybe there are marketing geniuses developing these ads. Maybe they attack our brains on some level and make us vulnerable to the content. Maybe that same woman doing the dance for which she would be laughed out, were she to do it in public, can succeed where other ads do not.
I for one, would prefer it stop. The intertubes promise to offer something in advertising that has remained elusive, though something originally intended with it. That is actual useful information at the touch of a finger. Our minds are so used to ads lying, exaggerating or obfuscating, that we probably would not know what to do with the truth. But where print ads, radio and television cannot easily answer our quality/price/availability questions, the internet ads could. If only they would.
Sigh.