We can pat ourselves on the back for being popular enough to attract spammers.
How should we define spam and what should we do about it?
How should we define spam?
A typical profile of a spam user is someone who:
What should we do about it?
If it's clear that every post from a user is spam, then a moderator needs to delete their account (note: this is Stack Exchange policy). Otherwise, we give them the opportunity to change their behaviour. Leave a comment on their spam posts like:
If there is no change in behaviour then start suspensions for 7 days, and then double that for each re-offence. Also delete all of their spam posts and/or remove the spam content from quality posts.
If you suspect spam in a post, then it's really important that you flag a moderator for the suspicious post (otherwise we might not see it). We can then perform further investigation.