Having once been responsible for the multi-million pound publicity budget at a big multi-national, I know a bit about the black art of commercial sponsorship. So let's be clear, whether the subject is Formula One motor racing or the Paralympic Games, there's nothing altruistic about it. Dress it up how you like – and boy, does it get dressed up – sponsorship is advertising with knobs on; the knobs usually being the massaging of egos, the polishing of tarnished images, a quest for betterment and/or the satisfaction of personal indulgence.

Let me explain.

First, the advertising bit. Usually, but not always, this is about selling more product. It may be disguised by the marketing people as being about brand loyalty and maintaining market share (among the favourite excuses used by the tobacco industry, which takes this stance to deny its ambition for general market expansion).

Sponsorship is unlike proper advertising, which often has some artistically creative aspects to it and, generally speaking, can boast a certain kind of honesty. It says: I am a poster/TV commercial/newspaper ad. Here you can read words or view images put together in such a manner as to waylay you for long enough to proclaim the virtues of, and thus increase your propensity to buy, this car, holiday or mortgage.

Sponsorship is sneakier. It trespasses where it has no real right to be. It wages a war of attrition, seeping subliminally into your sub-consciousness.

It whispers conspiratorially in your ear: Remember me? I'm one of the good guys; I'm integrated with your independent editorial, even approved by the BBC; I bring you your beloved sport; support your favourite team, deliver the arts event which, without my largesse, would cease to exist.

It can be cynical. I know a company that refused to sponsor its local football club for fear of being seen as parochial, but changed its mind a few years later when appearing to be parochial was deemed to be good PR in the cause of taking the edge off some lay-offs.

I've known colleagues who signed cheques for causes they hoped would give them a leg up the honours list ladder and bosses who believed that buying into ballet meant they would go to the ball and secure a seat at the banquet alongside a princess.

Tickets for which most people have to exchange hard-earned cash are provided as sweeteners, backhanded in return for corporate funds, but dispensed as acts of personal generosity by big wigs for friends, family and favourite customers to swank in the best seats.

None of this is very edifying. However, it takes two to tango.

The beneficiaries of corporate patronage argue that their events would struggle to survive without sponsors. Witness Locog's spirited defence of its hardly health-inducing backers McDonalds and Coca-Cola.

Locally, for example, Norfolk and Norwich Festival director William Galinsky says: 'Despite significant investment from our funders and our first three-year commitment from the Arts Council, each year our team has to raise in excess of an extra �500,000 to ensure the show can go on.' That extra cash means 'the festival can make a huge contribution to the cultural life of our region and our country'.

Fair play, although it's interesting to note that it's the city's law firms that can mostly afford to provide that support and I'm unsure as to how positively I feel about a boast concerning 'the number of businesses signed up to entertain clients at the Spiegeltent trebling'.

Nationally, our old and generous friends the banks lead the way. State-owned RBS, for example, has a new approach to sponsorship built around the ethos that 'by giving back to society we begin to rebuild our connection with the communities we serve'. A sentiment that will have a few hard-pressed businesses in search of a loan choking on their Corn Flakes this morning.

Nonetheless, all this, you might argue, is symptomatic of no more than the well-greased runners of commerce sliding along their oily track. And you would be right.

Which makes the latest controversy to assail the world of sponsorship all the weirder. Why would a global IT group like Atos want to be a sponsor of the 2012 Paralympic Games? Its subsidiary, Atos Healthcare, has a government contract to assess whether or not disabled people should be sent back to work or have their benefits cut. Does it believe its involvement (and the group argues that it has supported the Games for a decade) will inspire the workshy to work, or win the company more outsourced government contracts? Were Atos, the government and the Games organisers all unaware that angry voices among disabled people see its work as contributing to a policy that has driven the victims of harsh judgements to suicide?

The government says that it is 'disappointed' at protests against Games sponsors. London 2012 chairman Lord Coe says that he's pleased Atos are at the Games because 'they are helping us'. Atos boss Thierry Breton says his company's vision for the future is 'to accelerate progress by uniting people, business and technology'.