Research 17 November 2017

Thomas RUSPIL's PhD defense

Thomas RUSPIL will defend this thesis "E-Opinion Leaders (e-OL) identification on internet social networks is a major issue for marketing managers.

Director : Eric VERNETTE

Jury members :  

  • Delphine DION, Associate Professor, ESSEC Business School (rapporteur)
  • M. Jean-Luc Giannelloni, Professor, IAE de l'Université Grenoble Alpes (rapporteur)
  • Mme Sandra Laporte, Associate Professer , HEC Montréal
  • M. Laurent Bertrandias, Professeur, Toulouse Business School, Université de Toulouse


This thesis deals with the role, status and identification of these e-OL. Each one of these three aspects are subject to controversial debates in the literature. Three studies are conducted within this thesis. They provide complementary and crossed answers to these debates. Regarding the e-OL status, we offer a definition for the e-OL concept in the specific context of internet social networks within three main characteristics: expertise in the product category, the will to publish valuable contents for their contacts, and the will to develop their social capital. Then, for the e-OL identification, we develop a new and multidimensional measurement scale for this concept. This scale shows good external validity. We confront it with others e-LO measures inspired by traditional OL measures, but also with alternative identification methods as the Twitter profile indicators and the Klout score algorithm. Finally, we test four models and their variants in order to better understand the origin and mechanism of the main e-LO role: the e-influence. We especially show that e-OL has an impact on e-influence. We also show that confidence mediates the link between e-LO and e-influence. These results speak to the relevance of e-OL in a viral marketing perspective.

Key words

e-opinion leader, influence, online social networks, measurement scale, viral marketing, trust