We have recently updated our SSL requirements. Please refer to the notice on our Ad Specs index page.
The PushUP is an auto expanding ad unit that is pinned to the users browser window. Once the page has finished loading the PushUP will start auto expanded (970x250) and resolve after 8 seconds. The PushUP will then resolve to 970x40 and stay pinned to the bottom of the browser as the user navigates the page. On CLICK of the pinned 970x40 ad, the unit will launch a 970x500 ad in the middle of the page and fade out the content to draw attention to the ad messaging.