[fragmede]

Net flows. A residential proxy should have a residential amount of traffic coming from it. If one IP has 1000x the usual traffic one household could reasonably account for, then mark it as a residential proxy. It won't be 100% accurate, but it's sufficiently accurate for reddit to go on a blocking spree.

[utensil4778]

How does one even get access to that kind of information? Are ISPs just selling this stuff or what?

[reincoder]

We have 700 servers around the world and we run measurements over all of the usable internet space, including assigned IPv6 addresses.

I highly recommend reading some of our blog posts and community posts.

You can also checkout our IP data tags page: https://ipinfo.io/tags