Social Networking Sites SPI
The WatchMouse Site Performance Index (SPI) quantifies the user perception of speed and availability of a site in a single number. The SPI is computed by adding up the time needed to load the main page, adding a penalty for each failed request. The higher the number, the lower the customer experience of the site. Sites with an SPI of 500 perform well, whereas an index of 1500 or higher is an indication of a seriously negative user experience. — Click this picture to view full size picture