Better VPN protection

VPN blocking now catches more VPNs.

Before, we only checked visitors against known VPN, proxy and Tor IP lists. Now we also compare the visitor's browser time zone with their IP location. If the time zone points to a country with a smaller discount, they get that country's offer instead.

Travelers going the other way keep their offer.

Also, we added more sources for VPN detection data.

No setup needed if VPN blocking is on. API users can pass &timezone= to get the same check.