Many events and causes produce web badges so that bloggers and sites can show their support. It is a wonderful marketing tool. If I attend a conference, I usually will put a badge on my site. But generally, I need to ask the event to produce a badge for me or make my own from their available materials. It is not practical.
The problem is that the Web Badges do not fit AIB standards. Bloggers with advertising on their site typically have blog templates that fit the IAB Ad Unit Guidelines. The Universal Ad Package (UAP) is composed by 300×250, 180×150, 728×90 and 160×600. These 4 ads are the most popular.
A good format for a Web badge could be 300×100 since it would satisfy bloggers who support the widely popular 300×250 ad unit. You must also take into account popular blog templates. Many blogs were designed to fit banners that measure 120×120, 125×125 plus various heights for either 150 pixels or 200 pixels in width.
Adopting both the AIB standards for your Web badges and the popular widths for blog templates means that it would fit the needs of all bloggers. Remember that any sidebar looks cleaner and more professional when everything has the same width. If you design a Web badge for an event, make sure you support all these standards.
+ AIB Ad Unit Guidelines