The real cost of social media is crowd control. You can only have a presence if its backed up with constant monitoring and rapid reaction. This we all know. We also know that the key to successful marketing is to be findable.
Too many companies square this circle by trying to be everywhere. Just like the old days of mass marketing, when they had to be on every time slot and every billboard, they now feel they have to be present on every social network and all over every fad.
The real solution is to identify where your audience will be and join them there in the best way you can. If you can't be the best you can in a particular location, then decide not to be there. That way you avoid outbursts of negative publicity while optimising your effectiveness elsewhere.