I don't think it's a good idea. Sounds like a marketing scam just for someone to make money. Especially with some low-time pilots they look to the captain for many decisions to be made. Now imagine this low-time pilot who has always had someone else there with them. I am a low-time pilot myself and am trying to be the FO that helps offer a solution and is not always Captain dependent. That would be kind of hard for someone to do if they have always flown with someone to walk them through any problem they encounter.