Vouch System
Vouches are a far better way to determine how trustworthy somebody is! They can ONLY be given after a successful deal and usually include the deal value in the comment provided by the other member. Checking somebody's vouches is always good practice before you choose to deal, but make sure you actually look at the reasons given for them. Many users have a high number of vouches, but they may all be low-value deals. A common practice of somebody who is "vouch farming" is having a high number of credit deal vouches with very few other types of deals. Most credit vouches are for deals under $10, so keep this in mind when dealing and ALWAYS use a Trusted middleman to ensure the safety of your deals.
Again, do not ask for vouches from people who haven't dealt with you! This is also against the rules and will likely land you in even more trouble than abusing the reputation system. Vouches are an integral part of the trust system here on OGUsers, and abuse of that system results in people being unnecessarily scammed by "multis".
To give reputation and vouches, simply go to their profile and press the + icon beneath the respective boxes. Reputation can only be added by upgraded members, however, anybody can vouch as long as they have more than 15 posts.