I think your analyses of all these methods is spot-on.
At Verifeed we use business intelligence gathered from listening and analyzing millions of social conversations to help consumer-facing companies like yours first to:
:: Find their "believers" or most likely customers (by geolocation, demographics, interests, needs, etc)
:: Understand what these folks are saying so messaging can be targeted directly to them to be more effective
:: Influence and "amplification" scoring so we can predict and focus on those who will drive powerful referral or "word of mouth" for you across all social platforms
:: Data-driven messaging then is effective in driving traffic, conversions and revenue
We use our own platform to find our own customers, and it really works. We can even discern customer intent. It's a more effective way of using marketing dollars, especially if you can get your happy customers doing the marketing for you.
Happy to talk further if this is of interest, and also point you to some other good social management tools for getting targeted messages out there once you have the "intel" at your disposal.
Best and good luck. I'd love to learn more about what you are up to!