It also compiles a Social Media Index, ranking firms on the number of online mentions they get on social media.

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DigitalCoCO tracks engagement around 60, 000 hospitality terms online and publishes the results as the restaurant social media index (RSMI).

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The comedic actress and writer's uncanny impersonations of vice presidential candidate Sarah Palin have netted her a Social Media Index (SMI) score of 8, 290, says "social advertising" firm Vitrue.

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Bradford believes marketers will use the index to measure their brands' levels of awareness in social media.

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It does, however, help to explain why a disproportionate number of the most influential celebrities on Twitter are African-American: On the Forbes Celebrity 100, eight of the top 20 celebrities in our social rank index are black, as are four of the top 10 social media overachievers.

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The folks at Timberland have a competing rating system called the Green Index they launched in 2007, complete with a snazzy website and social media-friendly branding.

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