Buy-and-Build and Add-On Acquisitions

A private equity fund buys a regional dental-services company for 7x EBITDA. Over the next three years it acquires nine smaller, independent dental practices, each for 4-5x EBITDA — well below what the platform itself trades at. When the whole group is eventually sold, the buyer pays 8x EBITDA for the combined earnings of all ten businesses, not just the original one. That gap between what the small pieces cost and what the combined whole sells for is not an accounting trick; it is the entire strategy.

This is buy-and-build: acquire an initial platform company in a fragmented industry, then bolt on smaller add-ons to it, repeatedly, so the group grows earnings faster and more cheaply than it could organically, while also becoming more valuable per dollar of earnings simply by getting bigger.

Why the arithmetic favors this

Three separate things happen every time a platform buys an add-on cheaper than its own multiple.

1. EBITDA grows by the amount the add-on contributes, funded partly with debt raised against the combined, larger company — which usually gets better lending terms than the small target could get on its own.
2. Multiple arbitrage occurs because the add-on's earnings, once absorbed into the platform, are valued at the platform's higher multiple rather than the small target's own lower one, simply because a bigger, more diversified, professionally run company is worth more per dollar of earnings to the eventual buyer.
3. Synergies — shared back office, purchasing scale, cross-selling — add real operating value on top of the first two effects, though they are typically the smallest and slowest of the three to show up.

Worked example

A platform earning $20 million EBITDA trades at 7x, worth $140 million enterprise value. It acquires an add-on earning $4 million EBITDA at 4.5x, paying $18 million.

1. Combined EBITDA. $20 + 4 = 24$, i.e. $24 million.
2. Value if the market still pays 7x for the combined group. $24 \times 7 = 168$, i.e. $168 million, versus the $158 million total spent (140m + \18m) — an immediate $10 million of value created purely from folding the add-on in at the platform's multiple instead of its own.
3. If the group is later sold at 8x (bigger, more diversified, so it re-rates further): $24 \times 8 = 192$, i.e. $192 million — an additional $24 million on top, purely from the multiple moving from 7x to 8x on the now-larger earnings base.

What this means in practice

Buy-and-build has become one of the dominant private equity playbooks in fragmented industries — dental and veterinary clinics, HVAC and plumbing contractors, insurance brokerages — precisely because those sectors are full of small, owner-operated businesses that individually trade cheap but collectively look like a scalable platform to a strategic buyer or the next PE fund in line. The strategy's return depends heavily on being able to keep sourcing add-ons at a discount to the platform multiple; if add-on prices get bid up as the strategy becomes crowded, the arbitrage narrows or disappears.