The scientific business model (but only sometimes)

An unfortunate reality. Some significant caveats however :
- Some journals require no or minimum payment per paper, funded instead by institutional subscriptions.
- Payment for access also funds the process of finding the reviewers. This isn't such a minor thing (witness that peer-reviewed paper about the time travelling alien octopus).
- Access doesn't always require payment, since virtually identical versions can be found on arXiv.
- While reviewing is done by other scientists, it's not really the case that they review it for free. Most institutes accept that reviewing is an essential and unavoidable part of the job, so reviewing is done on work time. Hence reviewers are getting paid for this - they're sacrificing their own research time, not salary.