I'm looking to trade gold intraday and therefore looking for a minimal avg spread. Through Dukascopy which is an ECN broker the spread seems to avg out around 30 pips, at least through Europe session. However other brokers seem to offer a spread down to around 10 pips. Can anyone explain how these would be able to 'beat' the ECN spread?

The futures contract is where most of the liquidity is, so matching the futures spread of 10 cents would be pretty straight forward.

Interesting. So you think they just make a CFD or similar based on the futures? though the futures moves in 10pips increments right? if so I guess the spread should never move under 10 for derivates of the future