Wednesday 21 January 2015 9.15pm
Gumtree and eBay are obviously very popular and in my view you'll get a better response on those. Gumtree is free to place an ad on, so I'd give that go.
Not sure of any specialist furniture-selling websites - I'd say it depends on whether the furniture you're selling is good/specialist as opposed to Ikea-type stuff - but the South London Press (local newspaper) has a classifieds section and it's free to place an ad. Slow but people regularly advertise so they must have some success.