How will you promote this? The big challenge is getting the word out to people with Flickr accounts. Another issue - I don't know if it's your problem or not -

How will you promote this? The big challenge is getting the word out to people with Flickr accounts. Another issue - I don't know if it's your problem or not - is people selling photos that don't belong to them by uploading copyrighted content to their flickr account and selling it from your site. But let's say someone buys an image without realizing it's copyrighted until after the purchase - do you allow them to get a refund or do you provide some way for them to report the problem?