Brainback
researchproduct design

Why we charge

The economics behind a product that could technically be free.

Jun 7, 20264 min readBrainback Research
abstract

AI tutoring has real per-message costs. The free tier is generous. The paid tier is honest about the math.

Sonnet-class inference is not free. Neither is Haiku-class classification. Every message in Learn mode fires at least one Sonnet call plus, often, one or two Haiku calls (classifier, leak guard).

The free tier covers 15 tutor messages per day. That's enough to build a habit — one problem set, a few explain-backs. It is not enough for cram week, or for a full-time student on a heavy course load. That's what Student ($12/mo) is for.

We chose subscription over usage-based pricing because usage-based pricing punishes exactly the students who are learning most. The last thing we want is a student closing the app because they're worried about the cost of one more attempt.

Parent ($20/mo) adds up to three student sub-accounts. This is a family-of-three price, not a small-classroom price. Institutional pricing exists too — but it lives on a separate track that involves an actual conversation.

That's it. No dark-pattern trials. No auto-upgrades. Cancel from the customer portal any time.


Written by Brainback Research. Published Jun 7, 2026. Filed under Product design.

if this landed, share it with the friend who’s outsourcing their brain

if the research landed

Put it into practice this semester.

Every essay here is downstream of a design decision inside Brainback. Come see the design.