As the Great British Beer Festival (GBBF) opens its doors today, event organiser CAMRA has revealed it has reached the milestone of 100,000 members.
And to mark the occasion every 100th visitor to the five day event at London's Earls Court will be given a voucher for a free pint of beer.
Mike Benner, CAMRA chief executive, said: "We are overjoyed at reaching 100,000 members, brought together by our passion for great British beer and community pubs.
"But while we may relax and raise a glass or two to celebrate at the opening of the Great British Beer Festival today, we are not complacent and tomorrow the hard work campaigning for drinkers' rights will continue."
CAMRA was formed in 1971 by Michael Hardman, Jim Makin, Graham Lees and Bill Mellor, when an idea of a campaign arose while they were bemoaning the state of British beer and pubs.
Membership levels rose sharply, with CAMRA boasting more than 5,000 members by the end of 1973.
Hardman said: "We would never have believed in 1971 that one day we would have 100,000 members.
"We would have hailed it as a roaring success if we had managed to attract 1,000 like-minded souls, but we didn't bank on the huge support that was lying in wait for just such a campaign to come along."
Over the years, CAMRA has campaigned on many issues and is currently calling for reform of the beer tie, fair taxes on beer, minimum pricing to stamp out loss-leaders in supermarkets and planning law reform to protect pubs.
In a recent poll to UK consumers, CAMRA asked the public what they thought the organisation's biggest campaigning success has been over 38 years.
A total of showed that 41 per cent said it was the continued existence of real ale in the majority of pubs, while 11 per cent said it was greater flexibility in pub opening hours.