I think the rules are fair. That they were posted quite a while ago, so everyone knew how it was going to work.
To be honest I tried to use some strategy in my submission, knowing the rules. I wasn't too worried about being a day or two late, but realized that many registered users would get several, if not all, of the entries in a category (like robynjh's comment#4). The winning skins will be the ones that got more users to download them while at the same time neglecting to download the competition. With that in mind I used an image that is somewhat striking and conspicuous in a gallery list. I also hoped to maximize my time on the "front page" by submitting on a Sunday afternoon rather than Fiday (not to mention I hadn't finished working on my entry till then anyway).
I also thought that in the CXP category in particular a winning-the-contest-oriented strategy would be to spend a lot of time on the preview image. The preview that catches the eye and gets that extra click to the details page has probably scored a download.
So, I hope no one thinks me sneaky for considering these things. I've always liked exploring the consequences of rules in games and things--big part of the fun if you ask me. The rules to me seem very fair. It would be hard to make a more equitable contest that depended on the community (while excluding drive bys and potential false hits) instead of a panel of judges.
