What is ISP?
ISP is referred to as your Internet Service Provider. This is an organization that provides services for accessing, using, or participating in the Internet. Examples of ISPs are: AT&T, Verizon, Spectrum and Comcast.
What is ISP Targeting?
This is a feature that allows you to set your ISP during your session. ISP Targeting allows your system to make requests to or from the ISP of your choice. For example: If you are subscribed to Verizon you could switch your ISP to AT&T for your session.
How is this done?
Just like setting your city, this can only be done via API request on either the Private or Premium services. In your curl request, you will need to add the parameter -country-US-isp-Sparklight (in this case replace 'Sparklight' with the ISP of your choice) when authenticating.
curl -x rotating-residential.geonode.com:10000 -U username-country-US-isp-Sparklight:password http://ip-api.com/json
Example to retrieve ISP list:
curl -x rotating-residential.geonode.com:10000 -U username:password http://api.geonode.com/countries/US/isps
This is what it will look like in your terminal when retrieving the ISP list: