Traffic analysis is the process of intercepting and examining messages or packets in order to deduce information from patterns in communication.
First used by military intelligence, but now it's use is more commercial-like in Internet surveillance. Big companies pay o lot to know when simple users surf the Internet, what they buy online and what sites are most visited. Basically your behavior and interests are tracked and recorded and are going to be used for economical or political purposes. While for the companies this means optimization and profit, for others this can be discrimination or interference in personal life.
Solution? There is no solution for the masses. Most people simply don't realize what's happening behind their Internet activities. They think nobody is able to track their activities. Others know it's possible but they think no one actually cares what you do online. But they are WRONG! As a consumer/buyer you are monitored because you need to be easy manipulated and in order to do that, they need to know as much as possible about you.
As an individual, you can start using VPN, SSH Tunnels or Tor.