New data from Double Click Adplanner shows that in June social networking site Facebook reached one trillion page views.

The data compiled by the Google-owned Double Click Adplanner show that throughout the month of June Facebook received over one trillion (1,000,000,000,000) page views and was visited by over 870 million unique users - an average of 1,149.42 page views per user.

Though this total number of unique users is significantly higher than the 750 million Facebook claims to have, anomalies in the number can be attributed to people visiting Facebook who are not members and existing members logging in from multiple locations.

Though these numbers are estimates generated from a variety of sources, including third party market research and external opt-in consumer data, they run contrary to recent reports that Facebook usage in early-adopting countries, such as the USA, was declining.

The site with the second highest number of page views throughout June was the Google-owned video sharing site YouTube, which registered 100 million page views and 790 million unique users.

Unsurprisingly, due to its invite-only policy and recent launch date, Google's social network, Google +, did not rank within the top ten.