Do you use the same ad across all your sites?

I know "repetition" sells. The more someone sees the same site advertised the more likely they are to join. If Im correct the average surfer is more likely to join after they have seen the same site advertised 4 times.

My question is this....
Lets say I have 10 tgps, free sites, top list in a particular niche and I have a sponsor that isnt saturated and I want to sell the fuck out of it. Is it smarter to make up "different looking" ads for each site? Right now I have the same exact ad on the top of all my sites (5 thumbnails that would make anyone into this niche mouth water. The thumbnails link directly to the join page). The fasion of my ad is not my question. The question is should I make up an entirely different ad for each of my 10 sites?

I share traffic between all of my site. I was just thinking that when a surfer sees the same ad they might think that the new tgp,freesite,toplist they landed on is the same owner of the previous site they were on because it had the same ad thumbnails and tactic. Should i fool them into believing that each site is of a different owner and the site im advertising is so great that 10 different site owners are advertising it? This is all part of the science of marketing. Whats your take on this.