Fatbat

Yeah, you're wrong. There's no such thing as a 468x80 in any standard ad units specifications, and there's no such thing as "American or European standards", the web is pretty universal. Look at the first link I sent you...

http://www.iab.net/iab_products_and_...1421/1443/1452

The IAB sets the standards, though admittedly voluntary, for ad units sizes so there is some consistency across the board. This makes it easier for big publishers to produce a set of banners without having to make 50-100 oddball sizes while missing the main stays and it makes it easier for site designers to define ad spaces on their sites with some predictability.

They've also defined a "Universal Ad Package" that consists of 4 sizes of banners "for the purposes of reducing the costs and inefficiencies associated with the planning, buying and creating online media. The result was the Universal Ad Package, a set of four ad sizes that all compliant member publishers have agreed to support."

http://www.iab.net/iab_products_and_...676/508767/UAP

Those sizes are...

300 x 250 - (Medium Rectangle)
180 x 150 - (Rectangle)
160 x 600 - (Wide Skyscraper)
728 x 90 - (Leaderboard)

and the media outlets that support this ad package are...

24/7 Real Media
ABC
adify
Adtegrity.com
Advanstar
Black Arrow
Break Media
Burst Media
Cars.com
Casale Media
CNET
CondeNet
Disney
Double Fusion
Edmunds
ESPN
First Light Net
Fox Interactive Media
Google
Kontera
Myspace
Panache
Seevast
Sports Illustrated
TicTacTi
The Weather Channel
Thompson Reuters
Time
Value Click Media
Vibrant Media
WebMD
YouTube

I would also say the 336x280 banner, or Large Rectangle (aka "Big Ad Unit), is widely supported by most news agencies, like CNN, the BBC, New York Times, MSNBC, ect. ect. In fact, most have a space that can accommodate the 336x280 as well as the 300x250 with a slight border.

125x125 or "Square Button" is pretty much the norm for Wordpress side bar ads.

Larger sizes are supported in their rich media and popup (interstitial) guidelines.

http://www.iab.net/iab_products_and_...767/Rich_Media
http://www.iab.net/iab_products_and_...76/508767/1461

The benefits to following some standards should be obvious. As is the case with most things "standardized", it makes things easier to plan and it's more cost effective. If a publisher doesn't have a standard size, and 3 of his competitors do, then he's going to be left out. I shouldn't have to ask to have standard sizes made, they should just be readily available.

I don't think you're going to be getting lots of banner clicks from people with ad block in effect because they obviously don't like ads and are probably not the sort that have ever even clicked a banner.