half page advertisements – new trend in internet advertising?

I keep a yahoo account for a high volume email list I subscribe to and was just assaulted by a HUGE advert for a Cadburys creme egg Mc Flurry at McDonalds. The thing was a 425 x 600 pixels image embedded in the page rather than a pop-up. I dont think i’ve seen adverts that big on a website before – i’m hoping that they had detected my bandwidth and screen estate before unleashing it. I wonder if this is a new trend – hope not.