Keyword loaded Popups

[tyrojds]

when i pause my cursor over certain banner ads on a particular site, a window pops up loaded with repeated keywords. what is the purpose of this and is it kosher? thanks in advance.

[BGumble]

Is it allowed? Sure. I don't see any hard limits on alt attribute length. It's called keyword stuffing and it's done to put the words where a normal visitor wouldn't see them. It's also attempting to pass keyword relevance to the site it links to.

It's widely suggested that repeating keywords in alt-attributes is a pointless task and they're more effective if used in human readable situations. You can achieve high keyword density if you just write your copy for this purpose.