If your forum is ranked well among search engines it is a good idea to make profit of that without causing inconvenience to the regular user. Thus it is a good idea to place a banner only for unregistered or awaiting verification users.

In vBulletin this can be done easily following these steps:

1. Log in your vBulletin admin area (e.g. http://yourdomainname.com/forum/admincp).

2. Go to Styles & Templates from the left menu. There choose Style Manager.

3. Click on << >> to collapse all options.

4. Then choose where you'd like your banner to be placed. In our case it will be the header so we double-click 'header'.

5. Then scroll to the bottom and add the following code:

<if condition="in_array($bbuserinfo['usergroupid'], array(1, 3))">

Your banner code goes here in HTML
</if>

The above code means that if the user has groupid 1 or 3 the following code should be executed. By default 1 and 3 user group ids belong to unregistered and awaiting-approval users.