Sky TV has a long reputation for seeking greener grass elsewhere, while the cut-throat markets in which companies such as Phones 4U and Time Computers operate make them perpetually promiscuous. Now Camelot, the National Lottery operator, looks set to join the band.
Agencies that win these accounts need to realise they're living on borrowed time from the moment the ink is dry on the contract. They invariably go out to pitch again sooner rather than later because of business problems that stretch the agency relationship to breaking point.
Stephen Woodford, the WCRS chief executive, recognises this. After five years of slog on Camelot, his agency has declined to repitch for the £24 million business.
While WCRS's heart might have told it to plunge all its efforts into retaining the account, its head has warned it of the futility of neglecting its other clients while chasing a lost cause. Fortunately, its head has prevailed.
Far better to know when a client relationship has moved beyond repair.
Maybe it's also a time for Camelot to reflect on whether the problems it is forced to confront are within advertising's power to resolve.
The fact is Britain has hit lottery overload. People are confused by the range of games so don't bother playing. Worse is the seemingly never-ending stream of bad PR. If it isn't Dianne Thompson, the chief executive, publicly confirming most people's belief that the odds against a big win are incalculable, it's the stories about National Lottery money funding a series of dubious initiatives.
Small wonder Camelot's ad strategy has lacked consistency and direction or that WCRS's creative work has been less than exciting. The Billy Connolly "Live a Lotto" campaign not only failed to halt declining sales but proved to be one of the most irritating series of commercials in recent years.
More recent work highlighting the good causes aided by lottery cash will always find it hard to compete with tabloid headlines claiming otherwise.
So what now? Abbott Mead Vickers BBDO is in obvious pole position to add the National Lottery account to Camelot's EuroMillions assignment it has just been appointed to handle. But until Camelot gets the product and the PR sorted out, not even the most creative advertising will persuade people to buy what they don't want.