The final version is available at: http://jis.sagepub.comThe aim of this work is the longitudinal study of the evolution and the state of 738 web sites in two different points in time (1997 and 2004). It tries to establish the rate of growth and decay of the Web and all the web elements. To this end, the structure and the contents of these web sites are extracted through a crawler and compared at the two different moments in time. The main results confirm a growth of web contents and elements in the web, although there is also a high degree of web content decay. The results suggest that in the seven year period covered by this study the web is characterized by both strong dynamism and instability.