Personally I do look at sales, feedback AND policies. Being a new shop I like to try and support shops that are also new to give them the opportunity to increase their numbers. And like Camilla stated if they have put the effort, with nice photos, a great description why not support a shop with few sales and feedback, after all you need to have sales to get feedback. But I do also look as policies. To me that's more important, I feel more at ease when a shop has clear policies, such as shipping and their return policy, it's not only a safe guard to the shop but to the buyer as well.
For example I had contacted a shop a while back about about a possible custom order, when I realized they didn't have any policies set up, I was hesitant and in the end decided that it just didn't want to take a risk. I had too many questions that could have been answered in the policies page. You know like when you go to a garage sale, you want the item to be clearly marked so you don't have to ask "excuse me how much" you can just make that informed buying decision just by looking at the price tag, determine if you want to negotiate that extra $.25 off, buy it, or just walk away.
~Felie