Mcfly Analytics
Trust posture: fixed fee in writing · change orders not silent creep · metric contracts before models · you own deliverables at handoff · NDA / DPA available · no pixels or MTA in scope · Stripe only after the letter is scoped.
How this becomes your signed letter: 1) Inquire · 2) 20-min discovery · 3) we fill brackets in this specimen → countersigned PDF · 4) Stripe deposit/desk-setup after signature · 5) kickoff → acceptance. Still a specimen until both parties sign — not an offer by opening this page.
Fixed-fee custom data science engagement
This is the letter structure serious buyers ask for before they wire a deposit: named fee, named deliverables, refuse list, acceptance window, ownership transfer. Productized decision desks — outcomes ÷ audited spend — not the Shopify app seat, not forensic media theater, not MMM SaaS. Review the specimen, then inquire on the custom hub.
1. Parties & purpose
Provider
Mcfly Analytics — Custom Data Solutions
[Legal entity / address as in signed letter]
Client
[Client legal name]
[Primary contact · title · email]
Purpose: design and deliver a scoped marketing data science desk where outcomes ÷ audited spend is the operating spine — with written metric contracts, fixed fee, and ownership transfer at handoff. When the outcome is sales, the spine reads as Total ROAS (period sales ÷ audited spend) with break-even from margin — average portfolio efficiency, not channel-level profit theater.
2. Fixed fee & payment
Total professional fee: $[AMOUNT] USD (fixed) for the scope in §3.
Typical payment schedule (finalized in signed letter): 50% on countersignature · 50% on delivery acceptance (or milestone schedule for Tier III).
After this letter is scoped and countersigned, Client may pay deposit / desk-setup via Stripe Payment Link. Payment Links are secondary to the SOW — never a substitute for written scope.
Third-party tools, cloud, CRM, or ad-platform licenses billed at cost when required — itemized, never buried in the professional fee.
Public bands: Desk setup $1.5–4K · Spend & Sales Audit $5–8K · Lead Gen Desk $8–15K · Advanced MDS $15–25K. The signed letter states the exact fee for this engagement.
3. Scope (tier selected in signed letter)
One tier is selected. Placeholders below mirror public packages; the signed SOW replaces brackets with named deliverables.
Tier 0 · $1.5–4K · ~1–3 weeks
Desk setup SKU
Spend paste / Sheet spine, Total ROAS, break-even from margin, Monday ritual card, handoff. Mid-ticket productized setup — see desk-setup page.
Tier I · $5–8K · ~2–3 weeks
Spend & Sales Audit
Platform spend rollup, invoice vs UI variance flags, sales/revenue period check, written close memo, 30-day Q&A on the memo.
Tier II · $8–15K · ~3–6 weeks
Lead Gen Decision Desk
Metric contracts (lead → MQL → SQL or client stages), spend joined to CRM, CPQL / efficiency vs targets, operator desk + handoff docs, weekly demos during build.
Tier III · $15–25K · ~6–10 weeks
Advanced MDS Build
Pipelines or Sheet source-of-truth, decision UI, rules-based allocation helpers, runbooks, production handoff. Optional retainer quoted separately at handoff.
3b. Cash-desk specimen language (when sales is the outcome)
Illustrative close structure — redacted SAMPLE figures only. Signed letters use the client’s period, timezone, and basis.
Total ROAS (action) = period sales ÷ audited ad spend
Break-even Total ROAS ≈ 1 / contribution margin
Period: [week/month] · TZ: [store TZ]
Outcome (Total / Net sales): $[X]
Audited spend (invoice basis preferred): $[Y]
Total ROAS: [X/Y]× · Break-even: [BE]× · vs BE: above | below
One action: hold | reduce | step-test [channel] with floor $[Z]
Reading: average portfolio efficiency — not channel profit, not causal lift, not “true ROAS.”
4. Included & excluded
Included (typical)
- Discovery call and written scope confirmation
- Metric definitions before models or desks ship
- Build work within the selected tier
- Weekly demo cadence (Tier II / III)
- Handoff checklist, credentials time-box, runbooks
Excluded unless addendum
- Forensic agency / rebate audits (~$100K class)
- Always-on MMM SaaS parity
- Warehouse / CDP rebuilds outside named scope
- Ongoing monitoring without a retainer
- Work outside the refuse list in §10
5. Client responsibilities
- Timely read access to ad platforms and invoice / billing exports
- Sales or CRM stage definitions and a named decision owner
- Margin or target-efficiency assumptions when allocation is in scope
- One weekly 30–45 minute touch for Tier II / III during the build window
- Prompt feedback on demos (delays may shift milestone dates without changing fee unless scope expands)
6. Deliverables & acceptance
Deliverables are those named for the selected tier (desk, memo, pipelines, docs). Work lands in the client’s cloud / Sheets / warehouse when practicable.
Acceptance checklist (all that apply): outcome + spend definitions match the metric contract; period + timezone match the demonstrated close; operator can complete Monday ritual without Provider present; credentials transferred / revoked per handoff; refuse list acknowledged.
Acceptance: client confirms in writing (email sufficient) within [5–10] business days of delivery notice that deliverables materially match the SOW, or lists specific defects. Silence after the acceptance window may be treated as acceptance under the signed letter.
Defect = material mismatch to named SOW deliverables — not a request for pixels, MTA, or “true ROAS.” Warranty is limited to correcting material non-conformity within a short post-acceptance window — not open-ended product support unless a retainer is signed.
7. Timeline milestones
Illustrative cadence; dates lock in the signed letter after discovery.
- Week 0 Discovery call · access checklist · fee & tier confirmation
- Week 0–1 Countersigned engagement letter · kickoff · metric contracts draft
- Build Weekly demos (Tier II / III) · variance / desk iteration
- Handoff Delivery package · ownership transfer · optional retainer quote
8. Data ownership & privacy
- Client owns its data and the deliverables created under the SOW (subject to Mcfly’s pre-existing methods, templates, and know-how).
- Least-privilege, time-boxed credentials; no standing admin unless the SOW says so.
- No shadow CRM of client customers; no identity-graph product.
- Public posture: Privacy, Security, draft DPA. Custom NDA / DPA schedules may attach to the signed letter.
9. Change control
Scope changes (new platforms, new CRM objects, additional models, forensic depth, etc.) require a written addendum with fee and timeline impact before work proceeds. Verbal requests do not expand the engagement. Small clarifications within reasonable interpretation of the SOW are absorbed.
Dirty source data may pause the clock or trigger an addendum for cleanup — called out early, not buried at invoice time. Fixed fee means Provider absorbs its own overrun on the named scope — Client does not receive a surprise “this took longer” invoice.
10. Refuse list
Out of scope always: pixels; multi-touch / path credit; view-through or “true ROAS” identity graphs; Triple Whale–class attribution clones; SyncWith-style connector zoos sold as Mcfly’s product. Operating metric remains outcomes ÷ spend.
11. Signatures
Specimen only — signature blocks appear on the countersigned PDF / DocuSign package.
For Mcfly Analytics
Name / title
Date
For Client
Name / title · authorized signatory
Date
This page is a specimen for buyer education. It is not a contract, offer, or legal advice. Governing law, limitation of liability, IP, confidentiality, and dispute terms are stated only in the signed engagement letter and any attached schedules. Consult your own counsel before signing.