Here're some interesting information about user's purchase at all Hotspots operated by HotSpotSystem.com.
In the first chart you can see that payments by PayPal are less than 10%. That's why it is important to accept credit card payments directly in your Hotspot (this is a feature which you can rarely find with other hotspot solutions).
Visa is ahead with almost 60% (including Visa Delta), Mastercard is below 40%. As you can see you can accept Visa Delta cards too in your Hotspot.