Virtuemart Likebox

Maaz,
The Like box isn't automatically added to Virtuemart products. You'd have to add this on your own, either by:
a) implementing the JFBCLike module and setting it to show on your VM pages
b) altering the VM views and adding the {JFBCLike} tag wherever you want it to show on your product flypages.

I hope that helps explain, but should you have any other questions, just let me know.

Thanks,
Alex