There are two locations for ad banners on a Guild Launch site - below the primary navigation bar and at the top of the right column.  All ad-supported sites will have these advertisements displayed on every page.

Guild Launch does a number of promotions for game companies.  On the left is a widget that was created for the Top Fan Contest that RIFT sponsored; also included here is a link to the EVE guide that was created for CCP, to give you an idea of what sort of promotions we have done in the past and what we can do for you in the future.

Here is the Eve Guide.