Surfers generally fear free trials these days... having been badly burned by many of them in the past. Pimproll is an honestly managed ethical sponsor that you can depend on to actually pay you for your sales... and they are releasing new sites and new tools all the time (so unlike many programs they clearly are in it for the long haul). I've done very well with them and continue to do well with them... I'd suggest you stop pushing free trials and see if your stats improve.
Also, it's pretty much impossible to decide if a sponsor is good or bad with only 5K uniques sent. Even just 3 sales in the next few hundred hits and your overall ratios would change radically. Contact them and see if they can assist you, they are very easy to work with.
