Eye contact is way too important. Having two eyes looking at you seems to make you more honest too according to the paper "Cues of being watched enhance cooperation in a real-world setting," found here at the NIH.

The study was conducted in 2006, but here's a more recent and interesting submission to the /r/DataIsBeautiful subreddit by Redditor celacanto.

The chart below shows the average amount of money contributed for a liter of milk (X-axis) and what picture was up in each week (Y-axis).



Basically, we can conclude that:

• Seductive eyes do not appear to be substantially more likely to compel someone to pony up.
• A neutral or angry expression does move the dial
• A creepy guy staring at you makes it increase substantially, case in point, creepy old guy.
  

Does this mean staring intensely at someone causes more cooperation from them? Try it out this week, and let us know how it goes.