I agree. It's not monetizable in its current state, but I'm curious what features you think would get it closer, such as:
* more rich replacement (including functions/regex) * dynamic content like stock prices * ability to chain expansions quasi-recursively * SSL / privacy
As a reference point, TextExpander (http://www.smileonmymac.com/TextExpander/) is an OS X app that offers similar functionality, and it's $30.