My two (Australian) cents. I initially advertised on Gumtree (Aussie equivalent of Gumtree) before I had a website.
I don't think it matters where you advertise or for that matter, where you find a writer. As long as the work is excellent, who really cares what the source is!
Earn Great Results
And by Aussie equivalent of Gumtree, I mean Aussie equivalent of 'Craigslist'. Oops... more coffee, please!