Advertising is a source of income employed by a minority of OA journals. Many of the larger, commercial OA publishers use advertising, but fewer of the smaller publishers or free-standing journals do.
A survey that is being conducted presently suggests a number of reasons for advertising not being exploited to a larger extent:
- Ideological resistance to advertising in scientific journals
- No or little knowledge of how internet advertising works and could be used in scientific journals
A general impression is that advertising cannot finance an OA journal, but it can generate enough income to be helpful. Probably, the level of income will vary greatly between scientific fields. It will, necessarily, vary by number of readers.