There is too much traffic on the internet, which makes it hard to find interresting data in it. It makes sense to create huge VPN company and put money into the marketing. That way everybody who has something to hide (and is willing to pay money to protect his secrets) will route his data through your infrastructure. So you basicaly have pre-selected traffic of potential criminals. Now you don't have to sniff all internet traffic, but just traffic of people who feel guilty.