Should I trust this VPN provider? More often than not, you can't and shouldn't.
We've already discussed the use of a VPN when connecting offices. Any time you have two LANs that need to link over the public internet, you should consider using VPN technology or an equivalent method of enterprise protection. In this case, the VPN software will probably run in a router, a server, or a dedicated VPN server hardware appliance.
We talked about two use cases above for consumer VPN services: Protecting your data and spoofing your location. We'll talk more about location spoofing later, so let's focus on data protection for now.
When you're away from home or the office, and you connect to the internet, you'll most often be doing so via Wi-Fi provided by your hotel or the restaurant, library, or coffee shop you're working out of at that moment. Sometimes, Wi-Fi has a password. Other times, it will be completely open. In either case, you have no idea who else is accessing that network. Therefore, you have no idea who might be snooping on your internet traffic, browsing history or online activity.
I recommend always using a VPN when using someone else's Wi-Fi network. Here's a good rule of thumb: If you're away from the office or home, and you're using someone else's Wi-Fi (even that of a family member or a friend, because you never know if they've been compromised), use a VPN. It's particularly important if you're accessing a service that has personally-identifying information. Remember, a lot goes on behind the scenes, and you never really know if one or more of your apps are authenticating in the background and putting your information at risk.
Another reason you might choose to use a VPN is if you have something to hide. This isn't just about folks doing things they shouldn't do. Sometimes people really need to hide information. Take, for example, the person who is worried an employer might discriminate against him or her because of their sexual orientation or medical condition. Another example is a person who needs to go online but is concerned about revealing location information to a person in their life who might be a threat.
And then, of course, there are those people in restrictive countries who need to hide their activity merely to gain access to the internet without potentially grave penalties.