As I've mentioned before, measuring the ROI of social media on a campaign level is pretty tricky and as Sandrine pointed out a couple of weeks ago, companies may need to take a long term view in order to fully reap the benefits of social media.

However, in theory, working out the ROI of a social media programme is easy (assuming you're measuring it over a long enough time period), as Olivier Blanchard shows us in this presentation:

Of course, there's a lot more more to it in practice (even without resorting to econometrics, which is of course why our consultancy services may come in handy):