The chart in the original post has in its title "Web-based e-mail". That chart represents the amount of time spent using web-based e-mail. Not the number of e-mails sent or received on web clients. Not e-mail app usage. And not mobile usage.
Mobile e-mail usage amongst teens has gone up 40%. Isn't that a more likely reason for the decline in web-based e-mail that an unquantified Facebook influence?
Here is the primary source: http://www.comscore.com/Press_Events/Press_Releases/2011/1/W...
The chart in the original post has in its title "Web-based e-mail". That chart represents the amount of time spent using web-based e-mail. Not the number of e-mails sent or received on web clients. Not e-mail app usage. And not mobile usage.
Mobile e-mail usage amongst teens has gone up 40%. Isn't that a more likely reason for the decline in web-based e-mail that an unquantified Facebook influence?