Recently, TechCrunch did a blog post that Tumblr has surpassed Wikipedia in page views per month with 6.5 billion page views compared to Wikimedia foundation sites's (Wikipedia and its sister sites) only 5.6 billion page views per month. Their reportage is based on data from ComScore, if TechCrunch had double-checked their source, they would have found that Wikimedia family sites, actually have about 14.6 billion page views. Unlike most other big websites that like to keep their analytic data secret, WMF (my employer) makes all the analytic data that we collect public. If you are a data nerd, you might want to spend few minutes checking stats.wikimedia.org. A side note we are committed to the privacy of our readers, and do minimum tracking. For example, we are one of the few websites that doesn't deploy cookies to track our users. We also use ComScore data to track our unique visitors since we don't deploy cookies on our website, and therefore have no way of figuring out our unique visitors.
Now, going back to the discrepancy between page views. There is obviously a big difference between 14.6 and 5.6 billion. But 14.6 billion is a more reliable stat since it is based on actuals, whereas ComScore data is based on a ComScore panel that has opted in to have their Internet surfing behavior tracked.
As for TechCrunch they should provide a clarification to their story. My colleague Amit Kapoor did point towards the discrepancy in data in the comments section.