The most affective ads that we have in that section are the ones the are the least "busy"
A picture of someone riding (with as few colors as possible in the composition) with Splitboard.com overlaid near the top, then 1 line of plain, descriptive elements along the bottom; GEAR, TALK, ADVICE
you could use some sort of illustration depicting a board being split in the middle and someone climbing the mountain in ski mode on one side and someone boarding down on the other. might be effective to have the three illustrations lined up in a diagonal and use the remaining corners for the logo and text.
the thing is you don't have much space, it might be best just to get the logo out there with some descriptive text. the logo does a pretty good job representing the site.
Given the limited space, it may be best to use the graphic contained in the header or logo or whatever you call it at the top of this page. I think this would be refered to as creating brand recognition...the consistant use of the same ID or logo. Just make sure the color pops a little better.
While it doesn't directly say "Hey!!! Buy a splitboard" it will direct those interested to the site. That will lead to happier advertisers....which should lead to a happier BCR