First go to the actual page here on facebook where you posted your ad.
Right click on the very top bar of page (where the web address can be seen). click on copy on the menu that pops up.
Go to your facebook wall.
You have to go to YOUR wall and not the general site where you see everyones posts.
In the blank box write a description of your item > then using your pointer (mouse) point to the little icons below the box until you see the one for 'link' > enter the address you copied from the page of your ad on the doll-mart site > click ATTACH >Now click SHARE.
You have now announced your item for sale on facebook and you will get traffic! I got 40 hits in 5 minutes!!