In close to 20 years at the broadcaster, he's earned almost enough to acquire a minority stake in Facebook. Of course, as the world's biggest Arsenal fan, Barnes would probably rather invest in his beloved football club. But whatever his equity portfolio looks like, there's no doubt he's done rather well for himself.
While C4's 2010 annual report isn't public yet, earlier figures show that Barnes accrued £5 million in salary, bonus and benefits between 1997, when he was appointed to the board, and the end of 2009. C4's 2008 report also shows that he was sitting on a pension pot worth £2.2 million.
Nice going. But then Barnes has put in almost 20 years at C4 sales since joining in 1993 and has perhaps built greater value at the business than many well-paid directors elsewhere. Last year, C4's share of TV ad revenue hit a high of 24.8 per cent.
On the downside, there have been times in recent years when Barnes attracted buyer criticism for appearing detached and disinterested. Yet he always seemed to be there when negotiation season came around.
Late last year, though, market speculation suggested that the 2011 trading season would be Barnes' last, and so it has proved. He's leaving with the blessing of the chief executive, David Abraham (Barnes will launch a consultancy when he leaves this summer and C4 will be his first client), but what next for C4? Certainly a chance to be progressive, after the "back to the future" move of last summer when Barnes surprised the buying world by recruiting the veteran Mick Perry as his head of airtime sales.
C4's rivals and media agencies are already suggesting that Gary Digby, enjoying his ITV pay-off for the time being but expected to return to the media world at some point, is the obvious replacement. And, to an extent, they are right. Yet Abraham has been consistent in his talk of the need to innovate in TV trading and Digby, apparently not ITV's idea of an innovative sales chief, hardly has a track record as a moderniser.
Then again, C4 seems to be up against it right now. It has reported difficulties over delivering targets on its ten-year UKTV sales contract, not to mention a battle to retain audience and revenue share in a post-Big Brother world where it is supposedly committed to "quality".
With these pressures and with TV ad revenue prospects looking gloomy again after the recovery of 2010, Digby seems a strong candidate. Yet with the prospect of significant change to TV trading regulations by 2013, C4 would be wise to cast the net wider.
Jeremy Lee is away.