Compete Stats vs. Real Stats (round 1)

Compete shows that Hacker News got 75,000 visitors in March...here:

http://grapher.compete.com/ycombinator.com_uv.png

PG stats show approx 110k + visitors:

http://ycombinator.com/images/traffic-24mar08.png

In the past my comparisons show that compete usually only shows 70-80% of the traffic a site gets. Is anyone interested in sharing some stats on their site ( I will do the same ) to get a better picture of how inaccurate compete really is?