Nesting limit. Replying to this:

Unless the blockchain contains access data?

Possible, but I don't think so. I'm not sure how they'd differentiate between people viewing articles and miners/witnesses/apps synchronizing the blockchain data. Even if it does, many of the sites out there copy the blockchain into their own local database and what we view is just a copy. Those sites could keep their own view counts, but I don't think they'd be able to pass it back to the blockchain.