This offer is for Silver members only via the spotlight tag on the dashboard. Therefore you cannot take advantage of it if you have a Gold subscription running.
Just taken advantage of it as my sons had recently run out. Got told about it when I phoned the live team up to haggle a deal.
Two free games also which are Aqua & Loadrunner, dunno what they're like but this is a cracking deal for just £26.50.Cheapest around even beating Amazon & Ebay.