I prefer Hotmail to Gmail; I like the new features and I like not having my mails mined for advertising. When I linked to pieces I did about Hotmail and the Windows Live Essentials Wave 4 beta, the discussion in the comments brought up a phrase in the Microsoft opt-out policy for personalised ads: "(b) the pages you view and links you click when using Microsoft’s and its advertising partners’ Web sites and services, and (c) the search terms you enter when using Microsoft’s Internet search services, such as Bing, and (d) information about the users you most frequently interact with through Microsoft’s communications or social networking services". I asked Microsoft's PR, Microsoft's PR asked two or three different teams inside Microsoft and we got an answer. I've written it up in full over on our 500 words blog but in short if someone in your Windows Live graph buys something, you might see an advert for something similar - but you won't know who, what (or probably why). The big question for me is, what are the lines that need to be drawn for ad personalisation and the ad-funded free online services?