Apple sells your data too. Hopefully this slide isn't representative of the talk itself, or it's pretty irresponsible.https://twitter.com/_sophiakc/status/913102828763324428 …
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
It doesn't sell it the same way but still makes it available to advertisers. Think you can opt out.
I'll dig out specifics once I'm at a non-phone computer. It's been a couple years since I looked into it. May have changed.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.