The decision to bring Lance Armstrong to New Zealand is puzzling even those who study marketing.

The drugs cheat who fell from grace is here to film an ad for Lion Breweries.

Canterbury University's Associate Professor of Marketing Ekant Veer told Rachel Smalley he's not sure what 'cautionary tale' they want Armstrong to tell.

He said it's still an odd choice, and it's hard to guess what sort of campaign would work with him.

Mr Veer said the company would have put a lot of thought - and despite his background - money behind the campaign.

But he said it's an expensive risk to take.

"We have heard that Lance is here to support Steinlager and we know that to have a drugs cheat here to support a brand that has one of their brands being Pure it is a little bit of an odd choice."