I have seen an increasing number of posts, and there have been several topics that have been reported lately, of members abusing the "rep" system, or just simply not using it as it was intended.
Please familiarize yourself with The Reputation System. Even if you think you know how it works, many of you need to be refreshed.
DO NOT demand or ask for rep points when giving away invites. It's called "Trader Rep". It is not intended for freebies.
Giving away an invite to someone, and trusting them in a trade is quite different.