Skill exchanges can work like torrents
If people want to learn, rather than simply outsourcing expertise, then they need educational objects and mentors. Especially when acquiring tacit knowledge, mentors are crucial. In light of this, a skill exchange can be set up so that students “leech” (i.e. acquire skills), while mentors “seed” (i.e. teach skills). Naturally, all users can do both at the same time with different skills, because most people have something to teach.