How does Rdbhost.com compare to other services?

I get asked, occasionally, questions along the line of 'Why should I use Rdbhost instead of a VPS?' or '... instead of Appengine?'...

Now there is a page on the website that attempts to address that class of questions, at:

http://www.rdbhost.com/comparisons.html

I am not going to rehash each comparison here in this blog-post, but am going to cover some generalities.

Most of the competitors are variations of web hosting or web server accounts. Each involves a fair amount of setup and custom configuration before it serves useful data. Most involve setting up an SQL database, and then migrating the initial database tables, views and other resources to that database.

Rdbhost databases are created with JSON and XML encoding built-in. Figuratively, ready 'out of the box', but literally 'already in the box'. Http request parsing and database querying, already in there.

The SQL queries themselves, you have to write, as they are necessarily custom to the project. What we can setup generically, we do setup. We even provide a means to restrict specific database roles to running only pre-approved queries.

There is also a cost difference, in that the hosting or server accounts charge by the month, so the minimum cost is always non-zero. For most business developers, this would be the least concern.

One competitor I looked at provided a web-service specifically limited to databases. CloudDB seemed to use a non-standard query language, which would lock users in to their service, once the code was written. I say 'seemed', as they have not seen fit to give me an account. If any of you do have accounts there, I would appreciate reading a review, or at least, corrections or enhancements to what I have been able to glean from the documents.

Comments are welcome, especially those that suggest competitors thay might be more of a straight-up substitute for Rdbhost.com.