Compete is regularly off by orders of magnitude and direction

Could you give an example of Compete.com being off by order of magnitude?

Could anyone here claim that Blippy.com is one of such examples? I'm getting downvoted for expressing my doubts in Blippy, but so far nobody made direct claim that Blippy is not on decline.

I would normally use Quantcast, but traffic to Blippy is so small, that it is almost off Quantcast's radar:

http://www.quantcast.com/blippy.com

Tipjoy's embedded js & iframe widgets were measured, not just views to tipjoy.com

This made things off by a 100X overestimate. Whoops!

Compete.com shows troughs, peaks and valleys for sites I've worked for, and the timing appears to have no relation whatsoever to real events and our own data.

What it is good for is comparing similar sites.

Such traffic misreports on Compete are typical for low-trafficked web sites. Can you show an example of a web site that is withing top 20000 web sites on Quantcast.com, but still has an order of magnitude inaccuracies on Compete?

How would I know the real measured numbers for enough sites to give examples?

If you specify just one example that would be good enough. I can give you my example:

http://www.quantcast.com/postjobfree.com/traffic 355,373 visits per month reported by Quantcast is 10% less than what Google Analytics reports (272,688 Visits per Month).

http://siteanalytics.compete.com/postjobfree.com/ 126,069 unique visits in March 2011 reported by Compete.com is ~2 times lower than Google Analytics shows for US traffic in March 2011 (252,621 Visits).

While Compete.com reports numbers that are two times lower, it shows trends correctly (overall PostJobFree.com growth; drop of PostJobFree.com traffic in December).