Last week we got the latest IAB figures showing a booming digital ad sector, helped by the continued rise of social + mobile + video. Today, a new global digital ad report is out, showing social search is one of the fastest growing segments of online search, which itself is still far and away the largest revenue-generator in digital advertising.

Deep into the findings of Adobe’s Global Digital Advertising Q1 2012 Update – a title only a search engine could love – comes this interesting fact: Facebook post engagement has grown 176% since the start of the year, thanks to the new pic-friendly Facebook Timeline. Here’s what it looks like in chart form:

This mirrors a study we looked at a few weeks back, which found the new Facebook format has boosted brand content engagement by 46 percent for 15 of the world’s biggest brands, including Toyota, Walmart, Coca-Cola and Ford.

The Adobe study also goes on to say that the global ad spend on Facebook has increased by 93% year-on-year, accounting for as much as 5% of global search spend. Looking ahead, the CPC rate (cost per click) for Facebook advertisers is expected to stabilize and even decelerate in the year ahead. And, fan engagement is expected to increase as more brands make the switch over to the new Timeline.