In the early hours of this morning bleary-eyed bankers and their clients staggered out of the Park Lane Hilton after a Christmas party that has become a by-word in the City for fun and excess.
The host was Mitsubishi Finance, which supplied its 500 guests with a three-course meal before turning the hotel into a casino. Dancing followed, and at midnight the party became a breakfast bar and anyone who wanted it could have a full cooked breakfast.
When the partygoers wanted to leave, taxis and chauffeurs were on hand to take them wherever they wanted to go.
The signal Mitsubishi is sending out is that it is a success. That it is fun and that it knows how to throw a party.
Such is the demand for a party that will say something about your company and outdo your rivals that professional party organisers are mushrooming like no time since the Eighties.
"Business is booming," says Nigel Peters of party producers Peters and Beech. "And it's not just quantity, its quality." As an example, Mr Peters cites how fashion house Prada this year recreated the swish Soho restaurant Quo Vadis in the midst of a party for 2,000 people. The waiters would take reservations for different times during the party and serve up authentic Quo Vadis food.
"You need to spend between pounds 100,000 and pounds 200,000 to really get your company talked about," said Sara Blonstein, who has produced parties for Channel 4 and Selfridges.
For Benetton, she had 20 rainbow-dyed sheep arrive in pink Cadillacs; for Channel 4, she created a post-apocalypse landscape inside Battersea Power Station; and for Selfridges, she recreated a Busby Berkley dance routine on a four-floor escalator using 150 dancers and actresses in full costume.
Other memorable parties this year included Channel 5's pounds 100,000 bash where 1,100 guests were entertained by eight bands on two stages. They were filled with sausages and mash, vodka and cranberry cocktails and if they got bored they could watch any one of a dozen specially created peepshows - sadomasochism shows, bikini-clad dancing girls and a chance for guests to try to wash the body paint off a model using water pistols.
Danielle Ney, who has responsibility at Channel 5 for its parties, believes they pay their own way. "We had a big party before the channel launched to which we invited Warner Brothers. They were wary of signing a film deal with us. After they saw the party they saw that we were a major player. That we were exciting and fresh and after the party they wanted to do business with us. The advertising agencies that came were increasing their forecast of the money we would take - after the party. It also helped to convince the TV talent that we invited that we were something special ...
"You need to know why you're having a party. If it's not part of a strategic plan, don't have one."