New web advertising concept?

Go to the Yahoo! sports home page and you'll see "Reebok" imprinted all over the screen as the page loads.  Refresh the page and you'll see it again.  After the page loads, a Reebok banner ad is displayed on top.  First time I've seen such a campaign.  Could also make sense on mobiles which generally have long page load times if the ad was very light (tried the Yahoo site on my mobile but it is not mobile optimized).  It would be interesting to see how such an ad is priced/valued - tons of low duration impressions added to the "permanent" ad.  Maybe because it is the first time I saw it but it did make me look for the permanent Reebok ad after the page loaded because I was curious to see if the campaign was integrated into the permanent page as well.