I was getting very good results from Google Products/Shopping, even when I was having to pay for it. Now it's a mess, as nearly all of my best-selling products have been disapproved (some seem to be disapproved because they're a different color than an approved product).
I need to advertise elsewhere, but I can't seem to find a suitable venue. Forum ads have never worked for me, as people come to forums to socialize, not to buy.
What's worked for you? What type of site has given you a good return on your ad dollars?