Terrific Guardian piece by Adrian Short. Excerpt:

When you use a free web service you’re the underclass. At best you’re a guest. At worst you’re a beggar, couchsurfing the web and scavenging for crumbs. It’s a cliché but worth repeating: if you’re not paying for it, you’re aren’t the customer, you’re the product. Your individual account is probably worth very little to the service provider, so they’ll have no qualms whatsoever with tinkering with the service or even making radical changes in their interests rather than yours. If you don’t like it you’re welcome to leave. You may well not be able to take your content and data with you, and even if you can, all your URLs will be broken.

The conclusion here should be obvious: if you really care about your site you need to run it on your own domain. You need to own your URLs. You’ll have total control and no-one can take it away from you. You don’t need anyone else. If you put the effort in up front it’ll pay off in the long run.

But it’s no longer that simple…