Some of the key a part from the those already mentioned are:
Visibility measurement: that is to say the traffic (number of users of the site):
The measurement of the entire traffic generated by the site. Traffic coming from both search engines and social networks. The measurement of traffic increase over a defined period.
Assess the relevance of a site:
Here it is to measure if the site achieves the community goal. The community’s popularity based on social
But for most commercial sites, sales measurement (ROI, Sales) remain the best indicator.