There was a trend a few years ago, in dealerships in the US, for a group of people to get together to buy one car and avail of multiple-buyer discounts.

Something like the smart-mob thing would work how anything akin to it (not just in terms of consumer activism) works in Ireland. The die-hards start it and carry it, but the membership stays at a trickle. (Maybe that's just cynicism after bitter experience.) I'd love to see it happen, though.