I don't know if any of you have used salsafundraising.com but we just did and the response was not too bad. The first time we did it the class of 23 kids sold 324 jars and we turned around did it again 2 month later and the same group sold over 700 jars.
It did take about 2 1/2 weeks for the turn around which is ok.
I think I'm going to use them again a Cinco De Mayo promo.