Tried Madbid to see what it was about. You buy bidding credits and bid for items. Each time you bid you use credits, this can be 5 credits for lower priced items or 15 credits each bid for more expensive items. When you do not win, which is the most likely scenario the bids you use are transferred into monetary credits. That's ok you may think but you cannot withdraw the money you can only use it to buy vastly overpriced items in their shop, eg Bitmore e storm Bluetooth speaker £41.99 + £9.99 post and packaging. This item can be bought on Amazon for £22.50 with free delivery. Best advice is don't be lured by the chance of a fantastic bargain cos if it sounds too good to be true, it is. And don't bother with customer service as they will just quote their terms and conditions. It may be perfectly legal but it is very shady.