Analysis By Torin Douglas BBC media correspondent

One reader bought the Sky kit for �100 and got a card from the BBC.

How big a deal is Sky's new free-to-air offer of 200 channels?

It played big on the BBC's TV and radio bulletins. It dominated page 3 of the Guardian, under the headline "Sky offers free 200-channel satellite deal to fight off soaring BBC service". Yet it was buried at the bottom of page 27 in The Times, which like Sky is part of Rupert Murdoch's media empire, under the sober headline "BSkyB to offer rival to Freeview".

Readers of BBC News Online were anxious to point out that it won't be the first time people have been able to get free-to-air viewing on the Sky platform. More than one challenged my assertion that "until now, satellite TV has meant pay-TV".

"What's all the fuss about the BSkyB 'new" free-to-air service'?" asked Bob Lowe of Blackburn.

"I took up a similar offer from Sky back in January 2001,which cost me �100, years before Freeview was available.

"I've never had a Sky subscription, and actually got my viewing card from the BBC."

Free satellite

Technically, of course, he's right. It has been possible to get a free-to-air card, but Sky seemed to do its best not to promote it or encourage viewers to "go free".

People had to work really hard to get their cards - it was easier just to opt for the lowest subscription package - so in public perception terms, satellite and pay were indeed synonymous.

Ofcom acknowledged this when it said that a free satellite option would be needed for digital switchover to be achieved.

Indeed, Bob vouched for this from his own experience: "The man from the satellite shop who installed my dish and box said at the time he'd installed 5 boxes a day for the previous 12 months, and I was the first free-to-air viewer he'd dealt with - he didn't know how to get a viewing card, although I'd already found this out."

Trading down

One intriguing question now is whether Sky's acknowledgment that free-to-air is a legitimate satellite option - to be actively promoted - will encourage existing pay customers to trade down and go free.

Sky sees no reason why this should increase. It points out that there has always been "churn" - the trade term for households cancelling their subscription - and since those people still have their box and dish, they can view the free-to-air channels.

Sky insiders say its churn rate has remained steady at 10%, even since the launch of Freeview.

Bargaining chip

Sharp-eyed observers have also pointed out a significant caveat in the small print of the Sky announcement.

The terms of the deal say the free-to-air entitlement is for 24 months. It's not clear what might happen after that. Could Sky revert to subscription only?

It won't be drawn - but if it were to withdraw the free-to-air option it would seem, on the face of it, a bad move politically, if not in business terms.

With the Government still committed to its timetable of achieving digital switchover between the years 2006 and 2010, and already testing the possibilities with a pilot scheme in Wales, any move that reduces the likelihood of switchover would not win favours.