Just to prove how popular some groups are in FB, Last week I sold 15 birds, some bantams and some silkies.. Monday I posted an add for 2 Silkie cross cockerels and was contacted within hours, they are GONE today!They are becoming more popular as time goes by. Try looking in a local FB group about chickens buy/sell/trade. I have sold and bought chickens from 'notices' in my local group.
Someone has also suggested Craigslist though I haven't looked there.