I havent done one myself but I can see it working well if done with the right people, for example you would have roughly the same amount of subscribers and views, that way it would be fair and you would be roughly equally promoting each other. How would you go about doing one of these yourself would you just send them a video to upload to their channel that you would have otherwise uploaded to your own with no mention of this taking place in the video?
Personally if I was to do that I would probably tell everyone in the video about what's going on so as not to confuse them. I think it would also be good if you were in the same niche, if one does gameplay commentaries and the other done personal life vlogs it could be very strange seeing that on a gamers channel especially if it wasnt explained in the video. I would try this out myself if I done videos similar to yourself because your videos are mostly about the people in them and getting to know them and swapping with another person who does vlog type videos would help both cross promoters get new people watching as you said and the viewers could appreciate the share.
