dear Robert and other math.SE website managers,
math.SE and its fellow sites have made a promising start and could certainly be, commercially, a "win-win" situation that delivers substantial and unique value to the users while earning profits for the operators. It is a public service to reinstate (some of) the functionality of the former USENET newsgroups, which for years have languished as, in effect, an unsupported corner of the Google search engine, and for this you have my gratitude. If the SE sites ever attain the levels of freedom and laissez-faire intellectual content sharing seen in the newsgroups --- and note that the runaway success of Mathoverflow is in large measure attributable to its greater openness compared to sci.math.research or specialized e-mail lists in topology, number theory and other math subjects --- then this reconstruction would in my opinion amount to a significant upgrade of the worldwide knowledge sharing and creation capacity, comparable to the advent of Wikipedia or the Arxiv. At that point my gratitude might be expressed in a more tangible form such as donations of money, time or software.
With that said, the commercial aspects of the site are SO Inc's and SO's alone. If it wishes to hire users in some form as a paid-for ad agency that is great. But to invite them to perform unpaid work for the commercial benefit of SE and its venture capital investors, seems rather cynical as far as the flow of benefits from this activity would be one-way and not the win-win model described above. For users to believe that they should promote the site, or even that it is in their interest for the site to prosper (rather than, say, growing in public mode and then privatizing via subscriptions) it would be important for SE owners to explain to what extent their vision includes a long-term cultivation of a major free knowledge resource, of value to all people, and not merely the creation of a neat and profitable web site or network thereof, driven by whatever commercial potential is seen by the owners and operators and investors.
This is not entirely a philosophical or hypothetical question of asking the SE management to provide gushing testimonials that they really "Get It". The actual site operation, although in beta, has often resembled an overmanaged parochial school, with concerns about trivia like homework, or censorship of postings on a pre-emptive suspicion of hypothetical (indeed, nonexistent) copyright issues, dominating the discussion. I would like to see evidence that the SE overlords, as one user amusingly called them, see the big picture and understand the role of freedom, non-commercial and academic (and some non-academic) interests, knowledge sharing and transparency in setting the direction of the site. Selecting cute slogans and logos and the appointment of enough twentysomething volunteer moderators to "manage" discussion is secondary to understanding what kind of culture, course of development, and goals the SE intends to promote. (For example, at the most basic level, it is hard to learn from the site documentation who owns and operates the site and what their backgrounds are.)
The potential is enormous but past privately run sites have failed or hit a ceiling through lack of vision, often stemming from a lack of subject matter expertise among the management. It would be a pity to see math.SE turn into an intellectually depopulated site predominantly shaped by energetic hackers with a math hobby, or users with high reputation from solving large numbers of calculus problems but who were never part of academia, or people who don't have experience of what USENET and other predecessors were like and what structural and demographic features doomed those forums. Before asking the users to promote the site, SE Inc should explain what they think their site is and can be. The level of articulation seen so far is mostly niceties like "run by the community", but the forum is open for posting more detailed statements or links to such.