I use the site to sell almost 4000 points. I mentioned my phone number in the ad. I wanted to speak to the buyer by phone since it was my first transaction.I got their Marriott number and asked them to send the funds through Paypal. On receipt of the funds I spoke to Marriott Destination Club rep and made the transfer. I called the buyer to let them know Marriott had confirmed the transaction. As I recall I placed the ad in September 2011 and was contacted in January 2012. The site was my only place I marketed my points. Some wouldn't want their phone number listed but I found there was a comfort level for me taking that approach and I wasn't even the buyer.