I have a love/hate thing with these companies - 99designs is not the only one out there.

In favour of them:

* they offer affordable logos

* you know exactly what you're getting for a fixed price

On the flipside, there is plenty wrong with these logos:

* Me too: if the logo's any good, there's a good chance someone else will buy it too. It would be like turning up to a party, and finding that you've got the same dress on (... a nightmare situation for some!)

* They look like $99 logos, or any other logo churned out by these companies

* It devalues the work of designers - a good designer understands what your company is about, and produces a fitting logo for you.

I'm sure there are many other fors/againsts than these, and it would be interesting to hear what others think of these services.