4 Bids in a row from same user?

I'm listing some headphones on ebay, and got excited to see 6 bids... but the first 4 were all from the same person with onle 1 feedback count. Is there a reason for this? Seemed a little weird. Thanks!

If that weird people win the bid, it is better for you to get the money first.
It is to anticipate bad case

Bidder1 places a $20 bid on a $0.99 item, then Bidder2 comes along and places a bid for $5, because Bidder1 has allready bidded upto $20 the auction will automatically put in a bid for Bidder1 until another bidder places a bid above $20.

Nothing weird, just how the system works.