where is D6's statistics_counter in D7?
The Statistics module shows you how often a given page is viewed, who
  viewed it, the previous page the user visited (referrer URL), and when
  it was viewed.
  
  In Drupal 7 configure statistics via configuration > statistics.
  
  To enable collection of statistics, the Enable access log checkbox on
  the Statistics settings page must be checked. 
  
  Enable Count content views to turn on and off the node-counting
  functionality. If turned on, an extra database
  query is added for each node displayed, which increments a counter.


Make sure you set permissions for the module at admin/user/permissions and configure it.

Based on drupal.org and http://groups.drupal.org/node/147619