When it comes to silly buyers - I think they have always been there - but the likes of Gumtree and Fleabay just give them more opportunity to demonstrate this behaviour !
Remember FreeAdds? I sold a lawn mower via this years ago and had quite a lot of interest. One chap said he liked it but had others to see and would I hold it for him. I said no, as I had another guy coming later that afternoon.
He said he would be back and I said if it's sold - it's sold.
He did come back - and it was sold by then. All he kept saying was "but I asked you to keep it for me!" - I don't think he was quite right in the head....
And I had a real nutter when I sold my GT6 via Exchange & Mart - I had phone call from a guy who said I would never sell it as I was asking too much money. I thanked him and said that "we will see."
It sold in a fortnight for marginally less than advertised. He rang again and flately refused to believe that it had sold!
Some people are really odd .......