By Nick Higham Media correspondent

Only a few short weeks ago wise heads were being shaken over Big Brother. The housemates were boring, the ratings were disappointing and the tabloid coverage lacklustre.

The Daily Mirror even branded itself the official anti-Big Brother paper, and ran daily articles rubbishing the programme and its participants - a wonderful case of a newspaper having its cake and eating it.

The programme, it was generally agreed, had lost its edge and its lustre.

When the participants became more interesting (even if mainly thanks to the ingestion of copious quantities of alcohol), and the coverage in other media increased as well, the newspaper columnists sucked their laptops and came up with new lines of attack.

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The public vilification of Jade Goody was tasteless and cruel. The latest series was even more demeaning to its participants and its audience than the first two. The programme was unseemly, manipulative and exploitative.

There couldn't possibly be another series. Right? Wrong.

Once again Big Brother has shown that it is to Channel 4 what Who Wants to be a Millionaire? once was to ITV1: a way to generate huge (by Channel 4 standards) ratings, enormous word-of-mouth coverage and a great deal of money.

Ratings

Overnight ratings for the final show of the series last Friday put the average audience at 9.4 million (with a peak of 9.9 million) - more than for the final programme in the second series, and around the same as for the final of series one.

For the first time ever Channel 4 got a higher share of viewing (at 22.6 per cent) across the day than either ITV1 or BBC One.

What's more the average audience for the series, at 5.7 million, was considerably higher than last year's.

And the audience share for Channel 4's digital spin-off channel, E4, has doubled thanks to Big Brother.

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There have been suggestions that the audience is more downmarket (not surprising given that it's so much larger) but with audiences this large to sell to its advertisers Channel 4 is unlikely to complain.

Money

Equally the show has confounded the critics who said it was no longer "water-cooler television" - that people had stopped talking about it.

A quick search in the BBC's cuttings service proves that: in the last month alone no fewer than 1,000 articles (precisely) mention Big Brother.

As to the money: the latest series reportedly generated almost �5million in text message votes and alerts, at 25 pence a throw.

A further �500,000 has come from subscribers to the Big Brother internet streaming service. And the 8.5 million votes cast on Friday night will have generated a further �2 million-plus for the phone companies and the broadcaster.

The notion that Channel 4, which last year recorded its first-ever loss would turn its back on a goldmine like this is absurd.

Big Brother is its single most lucrative franchise and the channel will milk it for all it's worth.

Who Wants to be a Millionaire? eventually went into a decline. No doubt Big Brother will too one day. But until then Channel 4 will squeeze every penny it can from the show.