Source Frequency

Also called: Citation Frequency, Source Citation Rate

Common prompts: "what is source frequency," "which sources do AI engines cite most," "AI source frequency"

Definition

Source Frequency measures how often a specific publication, platform, or expert is cited by AI engines when answering category prompts. It identifies which underlying sources drive the answers — the publications and platforms a communications strategy needs to win in order to surface inside the answer layer.

Why it matters

Citation Share is the output. Source Frequency reveals the input. A brand cannot move its Citation Share without understanding which sources the engines are reading in that category. Source Frequency turns AI Communications strategy into a placement strategy — earned media in the high-frequency sources, expert relationships with the recurrent voices, content investment on the platforms the engines actually pull from.

Example

A wellness brand maps Source Frequency across 50 prompts. Healthline appears in 78% of answers. NIH in 52%. Mayo Clinic in 47%. r/Supplements in 39%. Cleveland Clinic in 34%. None of the brand's existing PR spend is targeted at the first three. The map reorganizes the budget.