Content pillar
A big recurring theme every piece of content hangs off, so posts ladder up to a few topics instead of scattering.
See it
What it is
A content pillar is one of the three to five themes that everything you publish belongs to. Instead of a feed of unrelated posts you get 'we are the people who talk about X, Y, and Z', and a new idea either fits a pillar or gets dropped. Good pillars are named after a problem the audience has ('getting paid on time') rather than a part of your product ('the invoicing module'), because the problem is what people search, ask about, and forward to a colleague.
Reach for pillars when the idea list is long and incoherent, or when several writers keep shipping one-offs nobody can find six months later. Three or four is the working number: fewer and you repeat yourself, more and no single theme gets enough volume to build any authority. Each pillar earns a cadence, a format mix, and a named owner. The payoff compounds, since pieces inside one pillar link to each other and repurpose easily; they already share a spine.
Gotcha: a content pillar is not a pillar page. The pillar is the theme, a pillar page is one long hub page that an SEO topic cluster links back to. Teams hear 'pillar', skip the theme decision, and go write a 4000-word page. Second gotcha: pillars that are really formats ('case studies', 'the newsletter') do nothing for you, because a format is how you say it, not what you keep saying.
Ask AI for it
Propose four content pillars for [product] aimed at [audience], using [audience research], [search and community evidence], [sales objections], and [content inventory]. For each pillar: name it after an audience problem, not a product feature; one sentence on why we can credibly own it; the evidence that people care, citing the specific supplied query, thread, or objection it comes from; five example piece titles; and the format mix with a monthly cadence for a team of [N]. Pillars must not overlap, so if two could plausibly hold the same post, merge them. Then sort the supplied inventory into the pillars and name the one with the thinnest coverage. Anything the inputs do not support goes in a separate list labeled hypotheses, not findings, and no invented search volumes or quotes.