If you don't really care about security --- and I agree there are times when you shouldn't --- then by all means use the cheapest possible hosting option available to you. But if you care even a little about security, avoid shared hosting.

I really don't understand Mike Cardwell's objection; I don't think what I'm saying is controversial at all. I actually thought I was making a relatively banal point.

"Now, do you really care if some community bulletin board's database gets owned? Probably not. But I wouldn't run a shopping cart on a shared hoster."

I agree. tptacek is the one who disagrees with you. He thinks there is "never" a good reason to use shared hosting.

I'm not using shared hosting, no. Although I did work for a company that provided it a few years back. I'm just trying to figure out if you're actually being serious with your claim that everyone with a database backed website should be running it from isolated servers? If you actually understand the implications of this or if you're just making nonsensical off the cuff remarks? I wonder how many tens or hundreds of millions of servers that would add to the Internet.