Concerns about the accuracy of log file analysis in the presence of caching, and the desire to be able to perform web analytics as an outsourced service, led to the second data collection method, page tagging or 'Web bugs'.
In the mid-1990s, Web counters were commonly seen - these were images included in a web page that showed the number of times the image had been requested, which was an estimate of the number of visits to that page.