About 20% sell on Flippa currently; most that sell have a pumped-up perceived value orchestrated by the seller's network of shills. They fake interest in the domain while pumping up the price. A sucker stumbles on it when it reaches the Most Active page and drops a bid thinking no way can he win with all this bidding activity. As soon as he drops a legitimate bid, all the bidding activity suddenly stops and he's the winner (loser depending on your perspective).
If you don't have such a network and trying to sell new domains, I think your chances for success are slim to none. The only winner would be Flippa when they collect your listing fee.