TGP conversion ratios are extremely subjective. What works for one may not work for another. In this day and age find out who will list you. Then start refining your sales text until you get your conversions to where you want them to be. Since I'm a greedy bastard I always try for conversion in less than 1:100 and have had much success with that.
Starting off I would shoot for 1:1000 then keep working it until you get to 1:500 and start duplicating that and keep refining it until you get where you want to be. This time of year is very difficult for good ratios because mainly the hardcore surfers (the leech's) are the ones that surf. They can be converted by you need to have your "A" game on to get them to convert.
The upside of summer for a newbie is they get to try different TGP's and find out who will list them for the fall
