On occasion a post will arrive here on MSE where someone has spotted that a user has repeatedly linked to their own site across numerous posts and so calls them out on it in public, or it'll get flagged for mod attention without hitting a Meta site. Or it might just go unnoticed until a mod discovers it themselves.
So, it might be a nice feature for an auto-flag when a user links to the same domain 3 times on 3 different answers (I suggest 3, but that is negotiable) so that mods can intervene if someone is repeatedly spamming links to the same site without community users having to pick it up and then call the user out on Meta, or other such behaviour. Usually it's just the user genuinely having written useful posts about stuff themselves that benefit the answer they've already left, but sometimes it's closer to spam (We've all seen numerous "Oh, I have a plugin that'll fix that..." answers with no useful text content scattered across Stack Exchange / Stack Overflow).
I figure it's best for mods to deal with that before it gets noticed and therefore before it becomes a big problem.
I suggest an auto-flag in the same vein as the 'repeated closed questions by user X' or other such generated flags. Or possibly reference it in users profiles / other mod admin areas incase they suspect suspicious activity by them.
Would this be welcome / possible? Or is this such a fringe situation that the cost:benefit isn't worthwile?