It lets you list all the frags you have available for sale and the quantity available with pictures optional. And each person can click to request the frag with timestamp of when they requested it. The seller can then click to accept the sale for the user.
And it does the same for trades.
The Coral Database has been more of an eye candy and because (most) people only post pics of what they have, even if they never sold or not even planning to sell a frag of it.
Let me make one suggestion. I certainly wouldn't keep anyone from using what looks like a good frag tracking system (although I did have problems with it when I used it a while ago), but wait one week and we may have something integrated into the site that will handle a lot of this.