Certainly it has been a challenging year for many SEO firms. Google compounded the usual rough and tumble for them by rolling out some massive updates, which, for more than a few agencies, caused disruption across the board.

One of the biggest challenges of 2012 for SEO agencies was the ongoing roll-out of the Panda update. Google's Panda update principally dealt with low-quality, thin, and duplicate content and was designed to root out poor-quality sites from ranking highly in Google's search index. Although it did succeed in removing the glaringly obvious offenders, many complained that their site had been unfairly targeted. For many an SEO agency this presented some tricky challenges.

Next biggest challenge in 2012 for SEO companies was Google's Penguin update. This update came hot on the heels of Panda and caused misery for many webmasters as Google devalued their links based on their newest algorithm update. Penguin was designed to remove sites whose link profile was too unnatural, overly manipulative and too full of low-quality or spammy links. However, although Penguin did have the desired effect for Google, many complained that they too had been victimized.

Then along came EMD - the Exact Match Domain update. Many then saw their sites drop out of the rankings altogether. For nearly every digital marketing agency this presented a significant challenge because it was not too long ago that many webmasters were complaining that Google was unfairly favoring exact-match domains. The exact-match domain update was designed to isolate and remove overly manipulative use of such anchor text in the domain name in order to get an upper hand in the SERPS. Again many complained that their legitimate site had been targeted unfairly.

And lastly, but by no means leastly, Google's less-well discussed Venice update. This one seemed to fly under the radar compared to the other big updates like Panda, Penguin and latterly the EMD update.

The Venice update certainly changed how Google handled local search results but it ultimately had less of an impact (comparatively) on agencies and their clients.

"We launched a new system to find results from a user's city more reliably," explained Google about the change. "Now we're better able to detect when both queries and documents are local to the user.

'"This improvement improves the triggering of Local Universal results by relying more on the ranking of our main search results as a signal."

So, dealing with the seemingly relentless roll-outs of major Google updates, in addition to the everyday challenges of running an SEO agency has made this a difficult year indeed for pretty well every SEO agency across the globe.