So I was browsing this site on my iPhone, and it places an ad at the bottom of the page that is always visible. No problem with that, but when you start scrolling the ad doesn't stay stuck to the bottom. It only 'snaps' back to the bottom of the screen when you lift your finger.

It's really irritating to have that thing jumping around the page constantly.

I'm guessing right now it has an eventListener attached to 'onscrollstop' to compute where the bottom of the screen is in relation to the document, and then absolutely positioning the ad, causing the jitter.

I'm not sure how much control you guys have over the ad code, but the CSS properties "position:fixed; bottom:0;" would make it stick to the bottom of the screen all the time.