If you are a facebook advertiser there may be some kind of problem with what you pay to Advertise on the Website. I have noticed this problem because the first time I looked into facebook ads I noticed that they gave an option to pay per impression.
Now this can become a big problem when paying per impression simply because facebook will force users to make extra page views. Facebook is slow to refresh I get updates in Google apps email a.k.a Gmail to does of you that do not have a Domain name. Before I get any notification of new Messages in Facebook. This leads to increased page views because the social networking website is not refreshing the cache causing visitors to constantly revisiting the site and costing the advertiser money.
Using the Cache on sites makes sence to normal static sites or blogs that are updated only once per day. But if Zuckerber wants to charge advertisers per impression and does not show the current version of the webpage then he is nothing more than a cheat.
Have you paid for Facebook Adverts ? What is your point of view on this I believe that Facebook are cheating Advertisers just to save Network Bandwidth.