The present paper seeks to investigate the factors that influence doctors' purchase intention for supplementary professional services that have been recently introduced to the market and how these factors alter accordingly to the nature of the services. For that reason a theoretical framework has been developed and empirically tested using data collected from 100 doctors. All doctors were personally interviewed with the use of a structured questionnaire. In order to explore for potential differences depending on the nature of service, two different cases of services were used: a commercial service (e-detailing) and an educational one (on-line training).The results of our study indicate six factors that influence significantly doctors' intention to buy the addressed services. Three of them derive from the technology acceptance theory and the TAM model (perceived usefulness, ease of use and professional image) while the rest refer to the doctors' professional characteristics (work experience, current employee status, and familiarity with the on-line context). Another important conclusion of the present study is that the influence of the aforementioned parameters on doctors' purchase intention is different for the two kinds of services. These differences also imply that perhaps alternative marketing approaches are suitable for the two service contexts.