At first sight the recently announced deal between Microsoft and BT allowing UK Xbox 360 gamers to access BT Vision through their console seems like a win-win situation.

However, look a bit closer and things aren't all they seem.

Here's the catch...

BT Vision doesn't actually deliver live DTT/Freeview TV over a broadband connection into the home. Only the on-demand element of the service is actually delivered by IPTV. To receive Freeview via BT Vision requires a dedicated BT Vision set-top box, which is essentially two DVB-T tuners and a built-in 160-gig hard drive.

Granted, BT do throw one of these V-boxes in for free when customers sign up to the BT Vision service, although it's subject to a one-off £30 "connection fee".

The reason why potential Xbox owners might be confused is that BT is basically dressing two separate and distinct technologies, with different delivery methods, as one shiny package. Oddly enough, Monday's announcement of the Microsoft-BT Vision deal somewhat glossed over this fact. Maybe they thought their target market tech-savvy enough to understand the nuances of what they could or couldn't access?

Pay as you watch

What it all boils down to for Xbox 360 users is this: they won't be able to watch or record live Freeview using only their console and a broadband connection. BT assures us that it will be possible to stream or transfer Freeview programming to an Xbox 360, but only with the assistance of an additional set-top box, such as the BT Vision V-Box.

It's a far-cry from Sony's proposed PlayTV gizmo for the PlayStation 3, which is a combined Freeview (DVB-T) TV tuner and Personal Video Recorder (PVR).

Instead, what Xbox 360 owners will get is access to BT Vision's various on-demand pay services, which include films, "nearly-live" Premier League matches and TV shows.

Or will they? There's another potential catch here, because unless you've signed up to a 12- or 18-month BT Broadband contract you won't be able to access anything. Not even the on-demand services, for which you'll be required to pay up front for - either pay-as-you-watch or a monthly subscription.

"In order to receive the service you will need to meet the requirements set out online at www.bt.com/btvision," say the BT Vision T&Cs, "and your BT Total Broadband service must be activated and subject to a line survey test that we will perform."

It all goes to show that no matter how glitzy the PR launch, there really is no such thing as a free lunch.