Add more VPN / tunnel protocols such as SSH and DNS tunneling, SSL can be nice too.
Add special servers that enables us to use PureVPN as a mini private LAN between one`s logged in devices, for example, to securely access my desktop at home, while traveling with my Laptop, I understand you can use a dedicated IP for that, but it is not as secure as being encrypted end to end, also this is a simpler solution, this is a unique feature that your direct competitors do not have.
Sell add-on VPS (Virtual Private Server) service. If you/ your partners have all this infrastructure, why not sell VPS to people that want to have their own websites and other applications? If I entrust you with my security/ privacy, it seems natural to order such service from you, bundle price etc (good for hobbyists, games, Internet of things enthusiasts).
I think someone mentioned it before, some people would prefer cheaper monthly price for multi-year in-advance payments, please give this a thought.
When paying using a gift card, please be clearer in regards to whether one needs pays the same price, or how much extra does that cost so we know what amount to put on the card.
PayGarden will take the full amount you have on your card, people need to be aware of this.