The fancier type of banner is a flash banner. The great advantage of this type is that you can extensively use multimedia elements, e.g. advanced animations, and still save in document weight compared to animated gif banners with most basic animation features. Even interactive banners are conceivable.
Flash is a multimedia file format (.swf) invented by Macromedia®. The company also offers high class authoring software which produces best possible results. Small file size, and almost infinite possibilities, made the separate flash player to one of the most popular free browser add-ons. With flash even people using low speed internet connections enjoy sophisticated multimedia applications.
Flash can easily be embedded into websites. It's mostly used for classy website menus and stand-alone applications, but advertisers soon discovered the many advantages of flash for so called "rich media banners". Advanced animations, sound and even small videos are supported in combination with interactivity through actionscript.
One downside is that it's much more complicated to do flash banner ads. Producing a flash banner is not just click and go. It's a time consuming process which needs accurate planning. Weather it's worth learning to use a powerful authoring application to accomplish one certain task is questionable. Moreover, the software packages available don't come cheap.
We discovered quite a few flash banner maker applications online. So far the results we've seen have not really been convincing. But what should one expect? Is it realistic to set up an online application to make a custom banner which considers my corporate identity, my preferences and produces fancy results? It is cost effective - yes.
There's a good reason why specialized design companies employ trained staff to meet customer expectations. People with deep understanding of how animations work produce excellent artwork from scratch, not templates. If you want a flash banner that drives results, you should choose this way.