What it is
Total addressable market (TAM) is the total revenue opportunity if every workable account in a defined scope became a client. For a recruitment desk, that scope is usually the same boundary your ICP already draws: a set of verticals, a headcount band, a geography and the role disciplines you fill. TAM is not a list of accounts, it is a figure, an estimate of how much the whole opportunity is worth before you have contacted a single company on it.
The standard way to build a TAM is bottom-up: count the companies that match your ICP, then multiply by what an average client is worth to you, roles filled per year times your average fee. A top-down TAM starts instead from an industry-level figure, an analyst report on staffing spend in a sector, and works down from there. Bottom-up is the more reliable version for a desk, because it is built from accounts you can actually name rather than a market-wide average that may not reflect your niche.
TAM tells you whether a market is worth mapping at all. Everything else assumes the answer is yes.
Why it matters
TAM is the sizing question that comes before every targeting question. ICP defines the shape of the account you want. Market mapping catalogues every company that fits that shape. TAM answers whether the resulting list is even large enough to justify the effort, before a consultant spends a quarter building relationships in a vertical that could never sustain the desk's billings.
It also matters for the decisions above the desk level: whether to open a new vertical, hire into a region, or fold two small niches into one. Get TAM wrong and you either overinvest in a market too thin to return it, or walk past an adjacent vertical that was larger than it looked from the outside.
How boilr handles it
boilr does not treat TAM as a one-off slide someone builds once and files away. Because your AI sales employee maintains a live catalogue of every company matching your ICP, complete with headcount and hiring signals, the account count behind a bottom-up TAM is already there and stays current as companies form, raise and expand. Sizing the market becomes a read of the map rather than a separate research project.
That map lives in the Company Brain alongside the ICP it was built from, so the sizing logic does not disappear when a consultant moves desks. As placements accumulate, the fee data that turns an account count into a revenue figure sharpens too, which makes the next TAM estimate, or the case for opening the next vertical, faster to make and easier to trust.
