Sir Alex Ferguson snapped up a copy of the magazine outside Central Station where Ross Martin, chief executive of economic development organisation SCDI, had a pitch for an hour.
Actor and writer Greg McHugh and broadcaster Shereen Nanjiani were among the "guest vendors" who braved the wind, the rain and the indifference of passers-by to sell the magazine.
The Big Sell-off, staged in Glasgow and Edinburgh, was created by the Glasgow-based International Network of Street Papers (INSP) and The Big Issue and was part of INSP's annual International Street Paper Vendor Week.
In Glasgow, McHugh, star of such shows as Gary: Tank Commander, described his stint as an "eye-opener".
He said: "I have a bit of an easier shift because people were recognising me from the TV and coming up and getting a magazine that way.
"You still just get hundreds of people blanking you. It is a good reminder for me for the next time I am walking past a Big Issue seller, at least to say if you don't want to have one, 'No, thank you'."
Baroness Helen Liddell, the former Scottish Secretary, said: "I'm shocked at how many people are rude. Sometimes nowadays we can't afford the £2.50 [cost of the magazine], but at least be nice to the seller.
"I think the vendors do a great job," she said, then smiled as she added: "I'd rather be canvassing: canvassing is easier."
Angela McCracken, a partner with law firm Levy & McRae, said: "Selling the magazine is a very hard job. People have to be more aware of what the sellers endure every day in order to make what is a very nominal amount of money."
Ally Dawson, the former Rangers and Scotland player, and development manager (West) with Street Soccer Scotland, said: "What is important for the vendors is that they get a little bit of acknowledgement from people, even if it is just a quick 'Hello, how are you doing?' sort of thing."
Author Alan Bissett said: "You get a wee bit tired saying, 'Help the homeless, buy The Big Issue' over and over again, and obviously it's disappointing when people walk by, but the people who stop and buy give you some chat and wish you good luck, and they keep you going."
Tim Blott, managing director of The Herald and Times Group, said: "Some passers-by have been more receptive than others, but you'd expect that in this sort of weather."
For more on The Big Sell-off, go to www.street-papers.org/the-big-sell-off
You can watch a video of Greg selling The Big Issue here