At a time when the public authorities are modifying their financing methods in the social and solidarity economy (ESS) sector, moving from a subsidy model to a model based on calls for projects, associations do not need to 'other choice than to adapt to meet the new rules (Goujon Belghit, 2019).

Now, they are put into competition and must demonstrate the relevance of the projects they wish to promote. The question then arises of promoting associative activities and including them in a process of social innovation by using effective social marketing.

This research aims to understand how social innovations are diffused in associative structures. To deal with the diffusion phenomenon, we adopt a comparative approach with technological innovation in order to expand our literature review and move forward on solid foundations that have been widely tested.

The empirical research is based on a mixed methodology which brings together qualitative analysis from 27 associations (from two territories: France and Algeria) and quantitative questionnaire with 270 members of these same structures.

The results of the research make it possible to underline firstly that the dissemination of social innovations takes place in a non-linear, non-hierarchical manner and each actor is a dissemination agent, whether he is a project leader, partner or beneficiary. A holistic diffusion model is proposed and crosses six diffusion processes.

Second, we build an adoption model based on logistic regression that identifies the main adoption attributes. The study reveals that relative advantage, financial risk, social influence, geographic proximity and social commitment all influence the adoption behaviour of beneficiaries.

Finally, in a third step, we note the similarities and the differences that exist between the models of diffusion of technological innovation and those of social innovation.