The HTML5 Headache
Developing banners with Flash was easy. Part of the reason for that was that Adobe makes great software that enables designers and developers to build complex animations with relative ease. Then HTML5 showed up to change the game, but it has barely caught on. Why you might ask? Well, the answer is simple: lack of tooling.
Let me introduce you to a wonderful new tool named BannerFlow: http://www.bannerflow.com/
BannerFlow is a web-based tool that enables you to produce HTML5 banners in a very similar way to how it was done with Flash. Instead of writing HTML5 code you drag and drop images and text. It does not get much easier than that. To top it all off, they even host the banners for you and that is a huge time saver because HTML5 banners can be made up of dozens of files.
I am aware that there are many other HTML5 banner design tools out there, however, there is one aspect that all of them miss. That is tracking clicks on the banners. How other tools miss that is really beyond me, but BannerFlow nails it. They give you tags, you set them up as HTML banner in AdvertServe as you would any third-party ads and the click tracking works out of the box. No messing around with coding required, so that is why it gets my top recommendation.
If you want to get serious about monetizing mobile traffic you should definitely give HTML5 banners a try. They go far beyond what you can do with simple GIF animations. Even if your advertisers are not asking you for it yet, I suggest you learn about HMTML5 before they do so you are prepared to accomodate them.