I suggest getting some payd advertisements.
With that I don't mean pay for them , but get paid.
Google offers a very good service (adsense) , gets you 0.50$ a 1000 webhits.
That money then can be spend in paying for ads.
Also , if you get ads like google , you will be able to fill in a list of keywords for your site , which will then be displayed above normal non-advertising sites.

So , basicly , you gain money and activity.

And , what many people sayd already : install some sort of shophack (no , not uShop , I tried it myself aswell , it sucks).
Maybe if everyone here could ask friends that own a copy of vB , to look for that old shophack , I'm sure someone will find it....
Installing that would increase activity a lot.