Social advertising has become a seriously big business. How big? Ad revenue on Twitter alone is forecast to reach $950 million next year, and more than half of all advertisers have said that they plan to increase their social advertising budget in 2013, with an increasingly significant portion going towards mobile ads.

Bottom line? It all adds up to billions. And when you consider that, as a medium, social advertising didn’t even exist a decade ago, that’s a pretty amazing chunk of change in relatively no time at all.

This infographic from Unified takes a closer look at the history of social advertising.

(Source: Unified.)