Can Footer Slide Up Ads Increase Landing Page Conversion?

Have you heard of slide up footer ads?

They are these ads that "slide" up from the bottom of your browser. Great way to call attention without being annoying. They are as eye catching as pop ups and overlays, but a lot less intrusive because they happen at the very bottom of the browser - not where you are reading. See it in action here and here.

Footer Slider Ads could potentially help conversion rates because most users are generally less accustomed to this type of lead capture method. Everything I've read claim they do wonders for conversion (they may be biased), but regardless, these ads make the offers very hard to ignore.

Imagine asking for email addresses, zip codes, rss feed subscriptions, twitter follow requests, other lead gen/affiliate type questions... possibilities are endless.

Testing Ideas: Employment Agency Sign up Form Landing Page - Hirefox

Hirefox is a UK based web talent (web designers, developers) agency. Very clean and sleek design. Striking. However, my first concern when I landed was the black dark background.  I'd love love love to see an A/B test of this landing page using a white or very light background color. (I'll get to the why later).

More testing ideas below.