As someone else mentioned, the labor is typically free. It's done by volunteers for various reasons (including, but not limited to, prestige ... literally working for exposure).
Also note that publishing to a particular high-profile comp sci journal tends to cost on the order of 1000 EUR (last I checked, a few years ago), more if you want it to be open/public access.
In other words, journals will:
- Charge hundreds to thousands of EUR to authors (typ. indirectly, by charging their university) in order to publish papers.
- Charge hundreds of EUR (at best) per year to readers for access to said papers.
- Not pay reviewers for the work in reviewing the papers.
It's literally just glorified super-expensive webhosting.
Also note that publishing to a particular high-profile comp sci journal tends to cost on the order of 1000 EUR (last I checked, a few years ago), more if you want it to be open/public access.
In other words, journals will:
- Charge hundreds to thousands of EUR to authors (typ. indirectly, by charging their university) in order to publish papers.
- Charge hundreds of EUR (at best) per year to readers for access to said papers.
- Not pay reviewers for the work in reviewing the papers.
It's literally just glorified super-expensive webhosting.