I believe ALL the major search engines have already done such long before the Lenovo thing.
I got friends who use their smartphones when they go out to shop and do in store comparisons and such on what they are looking for. Both Apple and Android users have reported Adds for the things they looked for will show up on Facebook when they use their laptops and they never did the search for such items except on their phones and never used Facebook on the phones while while they shopped. We've checked this many times over a course of several months. Bing and Google and Yahoo search all do the same things as far as the adds showing up on Facebook etc.
I've never tried it with my phone yet because I rarely go out to shop and just got my phone shortly before Christmas.
My wife and several friends have been “playing” the Publisher’s Clearing House game for a few weeks. They have our phone numbers. None of us ever gave our phone numbers when we signed up.
If you want to see something really scary do a search for your name and pictures. For example, search for “John Smith (use your real name) photos” and see what comes up.