I've been using
It's quite amazing how poorly implemented that site is. For merchants they don't provide even such simple tools for updating the list of products they wish to be advertised, all at once, in batch mode. So if you have some products that are out-of date, you're out-of-luck. There's no apparent way to replace them, through a new feed. There's not even a way to delete a product listing, not even manually. Mind boggling. Hello, CRUD, anyone ?
Adding to this deplorable state, any requests to their customer service, via email, on 3 separate addresses, seem to fall on deaf ears. They're probably too busy spewing nonsense on social networks, as they appear to be overly active on twitter and facebook, instead of caring for paying customers.
Given this, I can highly recommend avoiding them. I'll be trying to get my remaining balance that's in my account and move to better providers.