Virtuemart
We don't currently have an option to automatically add the social buttons to Virtuemart. There are a few options for how to add them:
1) Modify your Virtuemart template files and add the {JFBCLike} etc Easy-Tags wherever you want the buttons to show. This is the most flexible from a positioning standpoint, but the most tedious to do.
2) Use the JFBCSocialShare module and configure the buttons you want to display. Add that module to any position that shows on your VM pages.
3) Use the JFBCSocialShare module and configure it to 'float', like the floating share bar in the bottom right of this and every page on this site.
Pinterest
Please make sure the Open Graph - K2 plugin is enabled. That helps JFBConnect determine the image to use when sharing, and Pinterest requires an image. The button likely isn't showing because the image is missing.
I hope that gives you some ideas, but if you need help with the above, just let me know.
Thanks,
Alex