In general, VPN has utilities for the following general user profiles
The employee - the one who has responsibilities to fulfill and uses a VPN provided by your company to access resources on those networks even when you are at home or traveling. If you do not trust the network to which you are connected, you can enable VPN and prevent them from intercepting the connection.
Who loves downloads - regardless of whether you're downloading legal or illegal content, this type of user does not want some company to blacklist it just because they're using torrents. Using a VPN is the only way to stay safe while using these peer to peer networks. For him, prevention is better than ending up in court or paying a very high fine for something he may or may not have done.
Who loves privacy - Whether you're in a totally free and open environment or a highly-monitored one, this profile uses a VPN to keep your communication secure and encrypted, away from prying eyes, whether at home or on the go. For him, unsafe connections mean that someone is always reading what they say.
The Traveler - You're out of the country and want to watch your favorite TV shows the moment they go on the air. You want to listen to internet radio stations that have a country filter or want to use a new service / application that looks great but is limited to a particular country or region.
A mix of the former - those who do not fit into just one category, but identify with a mixture of them. In any case, a VPN service can be useful for anyone who wants protection, handling sensitive information from work without being fired or for anyone who is hiding from anti-piracy bodies.
And even if you do not identify with any of these cases, do you still believe that you can benefit from a VPN? You should use one when you travel or work on a network you do not trust (read: a network you do not own, manage, or trust who you manage).