It would appear that while most, well many, well quite a few, well some developers are quite talented at developing apps, they are lacking in basic marketing skills. While it cost the developer for the privilege of being in The App Store, some of them put a rather steep price tag on their apps without offering a "lite" version. (Of course I mean steep when compared to most other apps and not compared to software packages for "real" computers.)
I have several apps that I tried in their "lite" version before buying the paid version. I look at developers like Cross Match Technologies, the folks who put out the Atomic browser. The paid version is a bank-breaking 99¢, but they also offer a "lite" version. This is genius on their part! While I am sure many people would have just shelled out the $1 to kick the tires, by letting people try it before they buy it, this virtually assures an upgrade to the paid version.
Developers, take your lessons from Richard Trautvetter, Sr Software Engineer for Cross Match Technologies. It is a great app backed up by simply elegant marketing.