Loaded and locked in
The lock-in with Caspio can be brutal as it is with most similar tools. Once you build your application in Caspio, you can't really move it. This makes sense, given the business model, which charges nothing up front and a monthly fee afterward. You pay only if your application is successful, and eternal devotion to Caspio is the price.
The costs, though, aren't steep. Caspio encourages unlimited users and measures the sophistication of an application by counting the number of forms and the data stored in tables. By contrast, Coghead and WuFoo count the full-time users, although both are trying to tweak their model to avoid charging for users who visit only occasionally. Caspio avoids the distinction between full-time and casual users entirely.
What is truly surprising about Caspio is how much it feels like a Microsoft product. While there are many programming idioms common in Web applications, Caspio sidestepped most of them and built something that will look very familiar to Microsoft Access users. I did a double-take when I pushed the "edit" button for a page because Caspio took me back to the beginning of the page's configuration wizard. You may be working in a Web browser, but It's just like using Windows.