that the number of 'hits' recorded by a hit counter is in any way related to the number of individuals who have visited the site.
Some hit counters record the number of pages that have been requested, whilst others record a 'hit' for each image on a page. If a page contained 10 images the counter would record 10 hits.
In the main I'm against the use of counters at all. Pretty well everyone knows that the starting figure can be set by the site operator, so few people take much notice of the counters when they see them. You can usually get far better information from your web host - just aske them to turn on stats for your site. Often they're turned on without site owners even knowing - try typing yourdomainname/stats and see if it works.