Mainly because we are tired of seeing people charge as much as fifty bucks for search engine registration. With Stratosphere, you get the quality attention you expect, without paying the hefty sum. This is especially important if you happen to be a webmaster for numerous sites. Because you can have a website all day long. However, if no one knows about it, then you won't have visitors.
Promotion is the single most important aspect of making effective use of a great website.
No promotion, no visitors. And chances are, no sales. Sure, you can submit to a few engines such as Yahoo, Excite and Lycos manually. But there literally hundreds of thousands of websites that also offer searching and linking, which gives you that much more opportunity to reach your audience.