In Today's economy innovation is a strategic issue that concerns all domains of activities. The service sector represents more than 70% of the GDP and employment in the developed and developing countries. Although services are of a growing importance and constitute a way of innovation in the secondary sector, only few researches are done in service innovation management. The main reason is that direct innovation in services is poor and mainly consists in the adoption or use of technological innovations coming from industry. We propose in this paper some investigations into services characteristics and examine the ones that are usually used to delineate products from services. The objective is to lay the foundation of a new delineation that can be useful to classify items of a same nature regarding their delivery system and their innovation possibilities, taking the technological changes into account.