Well, they have a fun little report out yesterday analyzing different factors of a profile picture and what combination will make the most attractive profile picture that people like to date.
From 552,000 online profile pics, they put two images side by side and ask people to make snap judgment on which one they will be more likely to date, after collecting over 11.4 millions of these inputs, the use the pictures EXIF data and made graphs and came out with the following analysis:
1. Camera Makes a Difference

Camera with interchangeable lens are obvious better than point and click ones, and camera phones are the worst. Just so you know that I've recently changed my camera phone from a Sony Ericsson to a Samsung, so I'm not getting older and uglier, it's just the phone, OK?

This graph illustrates 3 things: 1) It's practically impossible to take an attractive picture with a camera phone. 2) It's virtually impossible to take a bad picture is you're 23 or 28 years old. 3) No matter what pictures you take, no one would want to date you past the age of 45. Given OKCupid is not just a gay dating site, the shallowness goes beyond the gay community.

Also it seems that iPhone users have more sex than other cell phone users. I wonder if it has something to do with the apps or maybe iPhone users generally have higher incomes?
2. Don't Use Flash

Soft light can hide imperfections but flash exposes them. According to the graph above, turning on the flash adds 7 years to your face.
3. The Blurrier Your Surrounding Is, The More You Stand Out
The best pictures have a very low depth of field, the most attractive pictures have a f/stop lower than 2.5.

Blurring out the field allow the viewer to focus on you and get less distracted by other things in the picture.
4. Time Is Of The Essence


It is true what they say about the Golden Hour, the perfect time to take a picture is just after sunrise and just before sunset but there's an anomaly which happens around 3-4 am. I wonder if the late night pictures are of the less clothing kind. Avoid taking pictures around 9-10 am or 9-10 pm, it seems to be the worst time to take a picture.
So here we are, use a professional camera, use nature light around sunrise or sunset, blur out the environment and getting an iPhone is not too bad an idea either.