A treemap is a way of analysing large amounts of data in a small space

In this example the top 100 websites have been depicted in proportion to the number of unique users they received in January 2010

via BBC News – The top 100 sites on the internet.

Take a look at the Retail area. No big surprises but impressive numbers for sure! 121 millon unique users for eBay, or 111 for Amazon! wow!