This practice applies mostly in the context of a volunteer-based Collaborative translation initiative.
Recruiting and retaining good contributors is difficult.
Therefore, make it really easy for people to move from being "passive" readers of the content, to becoming at least a one-time contributor.
For example, add buttons or links to each page, that allow readers to contribute to that page. This could consist of editing a page to fix a mistake, or it could be a link that allows the reader to translate the page to a language in which it hasn't yet been translated.
Links to related patterns
- Anonymous Contribution is one way to allow this transition, without having to go through a registration process.
- In-Place Translation is another pattern that facilitates this transition.
- Wikipedia is the ultimate example of a community that facilitates the transition from lurker to contributor.