There's just one difference. "You are being advertised" is technically wrong. A product is being advertised to me, and yes, I have to look at it as a cost of using their service. They are advertising masses to the product companies, and product to the masses, but not 'personally me'. There's a huge difference here. I look at it more like a mutual contract between me and the 'free' service. They're not selling "me", it's more like you scratch my back, I scratch yours.
You are being advertised to based on the profile Google has built of you and the profile companies want to advertise to.
As such, your attention your time, based on your life, is being sold to advertisers. I don't see how being aware of this and being okay with this changes this fact? Of course there is a "contract" of sorts (which are always mutual) in play between you and Google, Google provides you with a service and you provide Google with whatever data you want.
Google in turn uses this to sell its product (people like you reading ads) to other parties.
I'm not saying this is inherently bad either. But the sentence is used to make people aware of the fact that companies like Google have something to gain from giving you something for free, which is something a lot of people hadn't thought about before or are aware of (especially when they are internet products). Thus I don't get the pedantry that this statement seems to evoke.
