Here is an uncomfortable truth about SEO: a lot of what gets sold as growth is borrowed. The traffic looks great for a few months, then a core update lands and it vanishes, because it was built on the exact shortcuts the update was designed to catch. Traffic that disappears at the next update is not growth. It is a loan, and the interest comes due.
What actually gets sites hit by core updates?
Usually some mix of four things: thin content that exists to target a keyword rather than help a reader, pages that compete with each other so the search engine cannot tell which one to rank, links that were bought or spun rather than earned, and a shaky technical foundation. Core updates reward sites that are genuinely helpful and demote the ones leaning on tricks. If your growth came from tricks, an update is not bad luck. It is the system working as intended.
Build on the things updates reward
The durable version is slower and it lasts. Write content that answers a real question well enough that someone would bookmark it. Map each page to one clear intent so your own pages stop competing. Earn links by being worth linking to, through real features and guest work, not a farm that gets wiped in the next sweep. Fix the technical basics so the site can be crawled and understood. None of this is exciting. All of it survives.
How do you know if your traffic is durable?
Look at your last core update. Did your traffic dip and recover, hold steady, or fall and stay down? A site that holds through updates is telling you its foundations are sound. A site that drops every time is telling you the growth was rented. If you are not sure which you have, that uncertainty is worth resolving before you invest more in content.
What durable growth looks like
One UK travel brand grew organic traffic 515 percent, and it held through two core updates instead of collapsing after them. No private blog networks, nothing that needed hiding from Google. A year on, the growth was still there. That is the only kind of SEO worth paying for, because the other kind you end up paying for twice.
If your traffic swings every time Google updates, that is the gap I would look at first. Send me the site and I will tell you what I see.