Have been reading a good review of Facebook's prospects, in the Financial Times.Several interesting points (and data about the company here), but I particularly liked the following:
Facebook aims to harvest information about users and use that as a basis for ever more targeted advertising: "But the issue is whether what Facebook does to increase the value of the data it collects makes users enjoy Facebook less and use it less. Users might start to think they are the product not the customer. Not a fun feeling." [my italics]
The article points out a contrast between Facebook and Google here: if I Google for "catering services for weddings" or "Ford body repairs", its reasonably likely that I have an immediate commercial intention, and some adverts along with the search results may not be too creepy. Whereas someone posting to Facebook that they just got engaged, or that some idiot just rear-ended their car is spreading news to friends: quite a different situation.