I must trust Apple now that they are not gonna mine this data and send it backdoor to advertisers and other interests.
Google, is doing exactly that with every search you do, FYI. Google also tracks every website you visit, for how long, what you looked at, what you clicked on, what you typed, how long it took you to type.
Google knows everything about you, and they actively sell that to marketers for their ad engine.
Apple makes money selling you hardware products, less than 1% of apple's revenue comes from ads. I trust Apple a lot more on this front simply because they have a lot less interest in selling my info to 3rd parties.