Which may explain why David Bell, the agency's chief executive, has just bet his WCRS counterpart, Stephen Woodford, £50 that the London agency won't be able to match the Manchester shop's three-year tenure of the account.
Bell has every reason to be sceptical - he and his team certainly seem to have put up with a lot, with Phones4U taking the relationship to the limit on various occasions. The agency was even made to hold meetings in front of TV cameras as part of Phones4U's involvement in the BBC's Trouble at the Top.
Over to Woodford. "I'll happily take Bell's wager as long as the winnings go to Nabs," he says.
Let battle commence.