Would you recommend certification in Google Analytics, AdWords, or any other areas?
Getting certified in anything you use regularly is almost always going to help your understanding of it—plus it looks great on a resume/CV!—so, certifications in Google Analytics, Adwords, Facebook Ads, etc. are all a wonderful idea. My personal favorite is the Inbound Marketing certification from Hubspot. Check it out: http://academy.hubspot.com/certification