Ah, SEO – the field where you’re always in control… until Google decides you’re not.

Take a look at this graph. Nothing changed on the site, but in March, traffic just dropped off. Google’s algorithm update decided the site wasn’t worth ranking anymore. Then, without warning, the August update hit, and boom, the traffic is back.
Moral of the story: Sometimes your site is fine; Google’s just having one of its episodes.
(P.S. If you’ve ever gone from hero to zero, then back again thanks to an update, you’re not alone.)
SEO can be frustrating. Google’s updates can seem random, and your site’s success can change even if you don’t touch a thing.