pulse360 is a great company to work with and you can make plenty of money with them since they have placements on huge sites. However, make sure to work with an account rep or you will probably spend a lot of money testing and they are a huge help in the learning curve.
Pulse360 is a pretty big ad network, their ads are ran on some of the ad networks like AdBrite, not sure if that's where I saw their ads. I never used Pulse360, but they seem to be legit to let you know.