English to Spanish Marketing Advertising / Public Relations measurements

In a book on the use of social media in the business world, there is a chapter on measuring the effectiveness of the different social media for a given marketing campaign. In English, the author is using the word METRICS, which in the IT field I understand perfectly well is "métrica". (examples: "the time to get at the metrics— and those of your competitors—is truly at the onset", "Some of the standard metrics you will want to consider..." and "Tracking your success through social media metrics")

However, although the use of social media is an online phenomenon, would its terminology necessarily fall under the purview of the IT field? When I googled both "métrica medios sociales" and "medición medios sociales" I came up with a goodly number of hits for both of them from a variety of sites that at least *appeared* to be presented by experts in the field.

So my question is, which term would be the most appropriate in a book about social media targeted at the marketing field? I am specifically interested in Latin American usages, since that is the target audience of this translation. I'd love to get as many opinions as I can on usage across as broad a range of Latin American countries as possible. Thanks so much!