A warning to Kiwi businesses to pick up their game, to avoid online shopping hampering future Christmas spending.

Paymark figures showed a boom in spending at the weekend, but it came after a quiet start to the festive season.

Retail expert Andrew Parsons says online shopping was one of several factors which influenced the slow start.

He says in general New Zealand retailers are a bit behind the game, remaining largely reliant on customers coming into their stores - but without providing an edge over online.