The first chart fails to correct for time (I'd generally expect more people to be using any service in 2007 than 1999, so the raw numbers don't tell me anything

The first chart fails to correct for time (I'd generally expect more people to be using any service in 2007 than 1999, so the raw numbers don't tell me anything). It is difficult to compare growth rates in the second chart because the two things we want to compare are stacked on top of each other. It's not clear if the growth rates are similar or different. The third chart similarly fails to illustrate its point. It's not clear if time spent online is remaining constant from year to year--increasing time spent on Facebook does not necessarily decrease time spent on Google. It's also unclear if search engines and social networking sites are competing for time--it seems straightforward that what Google sees as successful (users find results quickly, spend most of their time reading linked sites) is not what Facebook is trying to optimize (time spent on facebook.com).