SEO is an arms race. If you’re currently in #1 position for a lucrative search term, chances are the everyone from position #to infinity are gunning for you.
So, it’s not just SEO that is changing – it’s your competitors.
Maybe you’re not number #1 right now. Let’s say you’re number 4. The difference in click-through rate between the Top 3 organic results and the rest of page one is sharp – you want to be Top 3 if you can’t be Number 1. The only way to get one of those coveted top spots, of course, is to knock someone else out.
“This ain’t a scene, it’s a goddamn arms race”Fall Out Boy
This is why your SEO project (encompassing all aspects of SEO, SEM, UX etc. as we’ve talked about) will never be finished. Even if the “rules” of SEO stood still, even if Google finally said “Yep, cracked it, that index is getting no better than it is today” you would still be up against the changes, improvements, and additions your competitors make.
That’s why they’re called “the competition” and not “people who do the same things as me”.