Between the two paths of open access - green and gold - the later is the harder to develop and has the less support from the research community. The main difficulty is about finding a sound economic model. Open Access journals usually depend on two funding sources: subsidies and/or donations from institutions and publication fees from research units in the authors-pay model. These two ways of funding open access journals and books proved effective in some cases (Plos), but are not flawless. The Center for Open Electronic Publishing, a french initiative for open access publishing in humanities and social sciences, has recently developed a new economic model based on “freemium” for its full open access journals and books series, in order to address two issues: improve their economical soundness and give them more visibility in libraries. Freemium, the contraction of “free” and “premium”, preserves open access to information together with the marketing of premium services.