The number you take back to finance

Number six deserves pulling out of the list, because it is the only one that produces a figure rather than an improvement.

Cost per task. Not cost per token, which measures your vendor’s pricing. Not cost per seat, which measures your headcount. Cost per resolved ticket, per merged pull request, per closed claim. The denominator under the exchange rate. The other five are how you improve it; this one is how you report it, and it is what lets you argue the bill up when it is earning. No company under a blanket cap can have that conversation.

Objections, and one honest caveat

“Context windows keep growing and models keep getting better at using them.” Both true, and neither makes paying for irrelevant tokens rational. The Du result suggests length itself carries a cost that capability gains have not erased, and the compounding is structural: it gets worse as agents get more autonomous, not better.