SKU count and revision frequency matter more than total volume. A brand producing 50,000 units across three stable SKUs may remain well-served by a converter. A brand producing the same total volume across 20 or more SKUs — with seasonal drops, private-label work, and frequent recipe changes — typically sees the economics shift toward in-house digital once eliminated obsolete inventory and lead-time carrying costs are included. Payback windows vary by operation and should be modeled against your actual SKU mix, format requirements, and finishing investment rather than compared on per-unit print cost alone.