It's not a scam but believe me it's impossible to win anything decent and i'm not just being bitter because i can't win, let me explain.
I work as an IT analyst in the UK and i'd consider myself a good strategist. So logically... 1) I heavily researched the internet for every tip, blog and video available - so I knew how to approach it and what to expect. 2) I paid $60/month for Bid-Ninja which is software which gives you excellent stats on your rival bidders - without this i'd be blind & naive and felt it was a must. 3) I came up with a long term strategy which was to win auctions for 'bid vouchers' for a while, then once I'd banked a lot of bids - i would then load them all up on a big item I want.
So just to explain for people who don't know how it works, each bid you put down costs £0.40/$0.60, so if you put down 50 bids to win an item - it'd have cost you £20/$30 - then add in how much it went for and the excessive P&P/S&H costs. Also you can gamble your money and try to win 'bid vouchers', for example - there could be an auction for a '100 bid voucher' - which you'd ideally spend 1 bid (£0.40p/$0.60) to win, therefore you'd have just won £40/$60 worth of bids for only £0.40p/$0.60.
So how come i'm not doing so great? Well let me explain...
When I bid on 'bid vouchers' or any half good item, i'm constantly outbid by people who have stockpiled 1000's of 'bid vouchers' from their previous 'bid voucher' wins over the months/years. I know this because of the bid-ninja software I use - shows me how many 'bid voucher' auctions people have won and how many 'bid vouchers' they've spent in their Quibids career. No matter what you bid for (unless it's a cheap/useless/token item), someone with an almost unlimited supply of bids will always beat you. Also you know when people have an unlimited supply of bids when they'll spend like 130 bids to win a '100 bid vouchers'. Another problem is that people from all around the world are effectively bidding on the same things (though of course most are from the US). There's a site called Quibidsreports (costs $6/month) which shows you less busy times and stats and when's best to bid - but because everyone sees this, everyone (particularly the sharks who have stockpiled) will want to bid at these times.
It's an impossible game to win. If you do want to play and persist, i'd advise you to at least get bid-ninja to analyze and evaluate things.