Freeloader, the internet games site, has signed deals with BT and Unilever that will see the two companies advertising within its interactive games.
Freeloader, which is owned by the software development company Pure Entertainment, provides online games in exchange for customer information, allowing brands to advertise within the games themselves.
Unilever is using the portal to promote its Physio sport brand. Ads for the brand will appear on the Virgin game Viva Football as billboards surrounding the pitch.
BT Internet is placing advertising within the 3D game Mission to Mars as part of a drive to reach 18- to 35-year-olds.
Bob Dewar, the chief executive of Pure Entertainment, said: 'In-game advertising is attracting a lot of interest from advertisers because not only does it create excellent awareness but it also has the brand-building ability of traditional sponsorship. We are increasingly finding that major brands are recognising that this is a highly sophisticated advertising platform.'
Gadgetshop.com was the first online advertiser to sign up for integrated games ads when Freeloader began to offer such deals last November.
Gamers logging on to the site have to answer a few questions before they are able to go through and play the games online.
Freeloader stopped developing games last autumn. Until then, Pure Entertainment had been creating some of its games in-house as well as other gaming brands from external developers. Now the company offers games from other companies including Grand Theft Auto and Jimmy White's Cue Ball. In other cases, they are commissioned from third parties.