Ground Floor: This year may come to be seen as a watershed for the Fairtrade brand in Ireland. For the last decade, Fairtrade has been reassuring a small but dedicated cadre of socially conscious consumers that their coffee, tea, chocolate and fruit arrived in their market with no exploitative strings attached. Fairtrade meant co-operative. Fairtrade meant development. Fairtrade meant, as it says on the tin, a better deal.

But two weeks ago, to mark the start of "Fairtrade Fortnight", several high profile retailers announced they were switching to Fairtrade products. Marks & Spencer, O'Brien's, the Thomas Read group of pubs and Bewley's Grafton Street cafe all committed to Fairtrade exclusivity in either coffee or tea. M&S converted its entire range of 38 teas and coffees. Even Nestlé has launched a Fairtrade instant coffee - Partner's Blend.

The trend is clear: Fairtrade is going mainstream. When some of the biggest names in retail want a piece of your image, you're well on the way from being the little brand that could to actually doing big business.

The companies above all issued statements emphasising their dedication to social responsibility, of course, but O'Brien's executive chairman Brody Sweeney cut right through the woolly rationalising with a straightforward statement of capitalist logic: "This initiative is being led by consumers. They want Fairtrade and they want it now."

Guys like Sweeney know a growing market when they see it. Sales of Fairtrade coffee have grown 40 per cent in Ireland in the past year, according to Fairtrade Ireland director Peter Gaynor. Preliminary market research for this year shows brand awareness at nearly 50 per cent of the market and around 60 per cent in the more affluent segments. Most have positive associations with the mark and its motto: "A better deal for third world producers."

The Fairtrade calculus is simple. For a guaranteed minimum price for their product, Fairtrade coffee growers in the Third World join certified co-operatives that meet certain employment and environmental standards. Included in the Fairtrade minimum is a $0.05 premium - like a voluntary consumption tax - that must be invested in the growers' communities.

In a commodity market that has seen prices at historic lows in recent years, Fairtrade growers reap significant benefits, price protection chief among them.

From the consumer's perspective, buying Fairtrade is an easy way of satisfying a Western conscience that wants to help poor people on the other side of the world, but at the same time isn't prepared give up lattes. Their Fairtrade guarantee comes in the form of certified virtue.

From the buyer's perspective, Fairtrade offers an avenue into the luxury end of the retail coffee market without the hard work of building an independent brand. By leveraging Fairtrade's cachet among discriminating consumers, plain vanilla distributors like Bewley's or Robert Roberts can spread the brand's equity across their entire range of products, even if only a small percentage are certified.

This helps them compete with the successful boutique brands, such as Java Republic, that have actually put in the effort to make sure "fair trade" products are known for quality.

Also, retailers and distributors that pay the small Fairtrade premium for their beans can then turn around and jack up the prices of the end product, knowing that the conscientious customers will pay over the odds for a mug of steaming justice.

None of this is as simple as "little Fairtrade good, Big Coffee bad", however. In fact, the exploding consumer market for speciality coffees in the last decade has arguably delivered more in terms of price fairness for producers than Fairtrade's certification model. Starbucks, the Death Star of the coffee world in the eyes of many fair trade advocates, actually pays an average price of $1.20 per pound - about double the average market price and only six cents shy of the Fairtrade price floor.

Just to put this into perspective: Starbucks alone buys more coffee each year - in excess of 2 per cent of the world's production - than Fairtrade certifies for all its growers. In terms of relative impact, coffee connoisseurship may do more for Third World producers than ethical consumption.

This is where Fairtrade defies categorisation. Using a kind of ideological judo, the brand has managed to redefine consumption as a moral response to global economic inequality by using the power of capitalism against itself. Guaranteeing a minimum price for a commodity may be contrary to free market principles, but it's the free market that is choosing Fairtrade products in abundance.

It's no accident that Java snobbery and Fairtrade have developed in tandem. In a segmenting market where cheap often means lousy, Fairtrade is reassuringly expensive luxury choice for the discerning coffee drinker.

The unspoken premise of the fair trade ethic is that differences in wealth are always unfair. It's hard to imagine a market that could work without such differentials, though. Ironically, the success of Fairtrade farms depends on the existence of a consumer market with enough disposable income to artificially boost prices in far away, poorer places.

The trick now for Fairtrade and other models of ethical consumption will be to keep pace with specialisation. A niche brand that loses its exclusivity by proliferating indiscriminately risks undermining its own selling proposition.