[hydn]

In vb's case. Guest still have access to the forum content. I only see this useful for forums with deny permissions set for guest from browsing threads. In which case Google ads will be affected and a login will give Google access to content and thus improve targeting.

This will be useful for non vb sites that have paid membership where you have to login - (ex. site.com/members) - where if you don't have membership of a valid password you can't access any of the member content.

With vB and most forums you can access most if not all the content as a guest you simply can't post which does NOT affect Google ads.

In fact pages such as newthread, newreply, and compose PM will have low CTR since users are performing an action. There's only one forum for Premium Members on our site that blocks guest and regular members. However, premium members don't see ads on our board. Using this for most vB forums is pointless AS-IS.