Apply ads + lists layout only if ad is present

![screen shot 2014-02-20 at 18 06 11](https://f.cloud.github.com/assets/85783/2221510/c3f0690e-9a59-11e3-99bf-b5dfd3a6f787.PNG)

![ ](http://media.giphy.com/media/z5io3SM6BJeHS/giphy.gif)