The paper aims at arguing the importance of development and diversification at services level, and especially at tourism services level. To this end, the paper approaches the two concepts of development and diversification and briefly presents the circumstances claiming for development and diversification of services in tourism; it also reviews the benefits brought by the development and diversification given the characteristic features of the industry and presents the results of a research conducted among the tourists visiting the Romanian seaside. The conclusions of the research strengthen the argument for due importance that should be given to the development and diversification of services, since tourists' assessment of development and diversification level impacts the frequency of visit and their intention to revisit the destination during the next three years.