Vouching?

Are we allowed to post a "Vouch" on a users thread under the "Hire Me" section?

For example:

Huge vouch for "Blank". He/She has helped me a ton with my projects that I have given him/her and was able to get them done promptly for me. I definitely can vouch that this is one of the greatest services on ScriptFodder. Do not hesitate to deal with "Blank" as you'll get your money's worth!

Sorry if this is the wrong section for this thread.