Play.com has intensified its march on Amazon’s market share as it aims to double the size of its product exchange site PlayTrade.

It is offering users commission-free sales for up to 10 items on PlayTrade throughout January, in an attempt to lure more users for the service.

Head of PlayTrade Luke Taylor said the e-tailer wanted to take full advantage of unwanted Christmas gifts to promote the service, which soft-launched last March. “It is thought that£1 billion of unwanted Christmas presents are given. Over£1 million of products were listed on our site by Boxing Day alone,” he said.

The move came as eBay reported a huge surge in selling unwanted Christmas presents.

Play.com is targeting the market share of rival Amazon, which also uses trading among customers as a key part of its business. “You have to credit what Amazon has done. However, we are changing the game a bit – giving rewards to traders who use the main site through the Playfunds accounts set up for them,” Taylor added.

He said that his long-term goal is to make PlayTrade as big as Play.com. PlayTrade benefited from the£5 million extra ad spend that Play.com ploughed into its Christmas push on its core site.

Play.com has more than 6 million users and is expected to report sales of£365 million for 2007. Sales over Christmas were up 24 per cent year on year.