I assume that if you are not logged in to your gmail as you search, that they can’t track your activity and link it to your gmail in the form of ads. I’ve had no advertisements come into my Droid phone despite my many searches. They DO know my IP though, as I do google searches and I’m sitting there looking at ads from Corpus Christi. I did a search on a book, and later on I saw google ads like an hour later for Amazon featuring the book I searched. A bit interesting.
This is all guessing though, I don’t know how Google does their thing, and I haven’t read their new privacy policy.
All the ads I am served with as I surf the web are for companies from whom I have already purchased or they are simply advertisers on the opened site.
My husband is active on several specialty forums thru his Gmail and he isn’t getting ads from those market niches, except for those he purchases from on a regular basis.
I would notice Amazon books influencing the ads I see and I don’t.
It isn’t all that annoying.