Here's an uncomfortable exercise for any link building programme: take the links you reported as wins a year ago and check them today. Industry studies consistently find that 8–12% of built links change within a year — removed in content prunes, lost in redesigns and migrations, flipped to nofollow by cautious new SEOs, or displaced from listicles by someone who paid for your slot.
Do the maths on a typical agency retainer — or better, do it on your retainer:
Build 15 links a month and you place around 180 a year. At a 10% decay rate, eighteen of them — more than a month's entire output — silently stop existing. If your average cost per placed link is £150 in time and effort, that's £2,700 of delivered work evaporating annually, per client, while the report still says "180 links built."
A links-built number only ever goes up. A links-alive number tells the truth.
The four ways links die
Content prunes take the biggest share: an editor consolidates three old articles into one, and your paragraph doesn't survive the merge. Redesigns and migrations come next — URLs change, redirects get missed, whole sections disappear. Then there's the cautious new SEO who nofollows every external link on arrival, and finally the listicle displacement: someone paid for your slot in "Top 10 tools", and you were number 10. Only the last one is malicious. The rest are accidents — which matters, because accidents are recoverable.
Recovery is a race against the CMS
The good news: most lost links are recoverable, because most losses are accidents. An editor consolidating two articles doesn't hate you — your paragraph just didn't survive the merge. Catch it within days and restoration is one friendly email: the revision is fresh in their mind, the old copy is one click away in the CMS, and you can hand them the exact sentence and URL to paste.
Catch it at the quarterly review and everything is harder. The editor has moved on or moved jobs, the page has been rewritten twice, and your email reads like an audit rather than a favour. Recovery rates fall off a cliff with time — which means the real variable in link maintenance isn't persuasion skill, it's detection speed.
The recovery email that works
When you do catch a loss early, keep the ask tiny. Three sentences: you noticed the page changed in yesterday's update (specific date — it proves you're paying attention, not auditing); the link to your resource seems to have been dropped in the edit; here's the exact anchor text and URL if they're happy to restore it. No guilt, no SEO jargon, no "as per our agreement". Editors restore these at remarkable rates when the fix is one paste and the request arrives within the week.
Beware the monitors that cry wolf
One caveat: cheap monitoring creates its own problem. A crawler that can't render JavaScript, or that treats one timeout as a lost link, floods you with false alarms until you stop reading the alerts — at which point you've paid for monitoring and still have none. A trustworthy monitor distinguishes "the page loaded and your link is definitely gone" from "we couldn't check today," and only raises the alarm on the former (or on repeated failures). Alert fatigue kills more link programmes than link rot does.
Make maintenance visible — it wins renewals
There's a commercial upside hiding in all this. When you monitor daily, you catch losses your client never knew were possible — and every recovery becomes a line in the report: "two links lost this month, both recovered within 48 hours." That sentence does something "15 links built" never can: it proves you guard the asset after you build it. Clients renew with agencies that protect value, not just agencies that produce it.
Links aren't trophies; they're livestock. Count them, yes — but feed them, check on them daily, and chase the ones that wander off while they're still in sight.