Nice article. It should be mentioned that from an IP address you can then guess a lot of information like where the device using this IP address is located.
If that's a user's IP address you can guess the spoken language and currency in addition to his/her location. That information can help you customize experiences for your users.
Here is a simple example using Python and Ipregistry :
from ipregistry import IpregistryClient
client = IpregistryClient("YOUR_API_KEY")
ipInfo = client.lookup("54.85.132.205")
print(ipInfo)