Personally, I would say our customer service, forum and directory among the other features and tools we offer.
Why?
1. Customer Service - I can assure you that no email is left unanswered! We do our best to answer emails to the best we can, if we have to do extra research just to answer a question, we do. We have staff readily available to answer support emails within 24 hours Monday to Saturday.
2. Forum - We have one of the most active forum's I have been on. We have a Community Manager who moderates and addresses forum issues. All in all you'll get help and extra info on the latest issues regarding online selling, eBay, products and other pertinent issues.
3. Directory - We have over 8000 suppliers and we're continue to add more each day. We have staff dedicated solely for finding and screening suppliers. We take a number of steps to ensure that suppliers meet our rigorous standards before they are added to the database.
* All our wholesalers must meet minimum standards of service. Most notably, we insist that suppliers provide secure payment methods so that in the unlikely event of something going wrong, members can always get their money back.
* We make anonymous purchases from all our suppliers and then rate them on price, speed, quality and service.
* Our three-tiered review system means that you don't only get our opinion on a supplier - you also get ratings from other SaleHoo members and independent eBay powersellers! You don't need to take just our word for it... find out what everyone else is saying, and judge for yourself.
* If a supplier receives a poor review, we keep both the supplier and the review in our database to alert other members. We believe that knowing who you can't trust is as important as knowing who you can.
Plus we honor our refund policy as stated

Feel free to visit us
http://www.salehoo.com/If you have any questions, please feel free to let me know. Cheers!