How We Protect Your Personal Data
We comply with applicable laws and industry standards when transferring, receiving and storing consumer data. Access to your personal information is limited to those Linden Lab employees who require the information in order to provide products or services to you or perform their jobs.

http://secondlife.com/corporate/privacy.php

According to this would they then not be in violation of thier own TOS and possibly open to lawsuits over it?

Also, although they have all that information, the relevant collecting, sorting and making all that useful so that it could be used as a point of sale method is far more difficult than just “we have the data, now let’s use it”

If anything, I could see them utilizing some buying data to provide more targeted advertising on xstreet, but I would see that more from the point of delivering more relevant banner ads from their xstreet merchants. In other words, what we have now on xtreet, but better targeted (which, necessarily, wouldn’t be a bad thing if that targeted banner ad helps you find what you were looking for in the first place).

The fact is, what we buy and consume in the virtual world many times has very very little overlap to the real world. In some people it may have more overlap. Speaking personally, I see very little personal corelation. Sure I may buy a virtual piano, but I think that gives very very very very little RL indication whether I may be in the market for a RL piano–music lover or not, it’s a money and space issue for most people, and usefulness too I would guess, you’d probably want to be sure you’re going to use the thing if it’s so expsenive and takes up such a big part of your RL home. In SL, I may just be buying it because I have an extra room to fill or imagine a sexy cool picture I want to take sitting on top of a piano. For an advertising buy, that small link is so tenable at best that it would not make a good buy for a advertiser’s dollars, certainly a much worse buy than, say, buying ads on a google search for piano.

I’m not saying that LL won’t go after more revenue streams, but I doubt it will be anything so blantant, in your face and annoying. Unless, of course, their other revenue streams dry up and they are forced into such methods.