Until the vendors raise the bar on the old Flash banner specs we need to try to squeeze out every unnecessary byte of html5 banners. More on the subject here. This is a must read by the GSAP team.
Since a little reading goes a long way the following two articles are very valuable when trying to accomplish tiny size images:
Two tools I use a lot (and can't live without) are:
The time you invest in educate yourself about image optimization will pay many times over in the future.