BumpedUp listing will be shifted at top and would keep going down with submission of new listing, Please keep in mind its not sticky listing which would stay always at top, nor it would be time based feature. Feature would work when listing are order by date as DESC
To offer Bumpup/RaiseUp listing functionality, Feature must be enabled in current listing package, For Package configuration visit and follow point number 4 to enable bumpUp feature, to set bumpUp price for each package visit and follow step 2 figure[1.3]
By Assuming that you have already enabled bumpup feature and set pricing, Click Configure link in front of particular listing from frontend user panel and then click BumpUp to top link from dropdown menu
By Clicking BumpUp to top link from dropdown menu, A modal window would appear, Hit boost button to bumpup that listing on top.