Monthly retainers force customers into commitment they aren't ready for. Project-by-project buying is too slow when work needs to start in days. Both options are common in software-delivery procurement and both fail buyers whose actual need is "execution capacity I can deploy when I'm ready, without locking myself into a long contract." VDC Packs — prepaid bundles of Delivery Units — are the structural answer.
This piece walks through how VDC Packs work, who they fit, and why pre-purchased delivery capacity is a different procurement pattern than either monthly retainers or per-engagement contracting.
Why monthly retainers scare customers
The retainer model — "pay $X/month for ongoing access to a team" — is common across agencies, contractor relationships, and dedicated-team vendors. It works well when the customer has continuous, predictable work to feed the team. It breaks badly when:
- The customer's work is variable month-over-month
- Priorities shift mid-engagement
- Internal stakeholders need to align before work can start
- The customer wants to start small before committing
In all of these cases, the retainer's monthly cost compounds while the customer can't deploy capacity effectively. The economic damage is invisible at first — the team is "engaged," the bill is paid — but utilization data eventually exposes that the customer paid for capacity they didn't use.
The retainer also creates psychological commitment friction. A CFO evaluating a $30K/month retainer with a 12-month minimum is committing to $360K of spend before the first piece of work ships. Even if the math is right, the procurement process around that commitment is heavy. Most managers don't have signing authority; legal review can take weeks; security questionnaires drag for months.
Why project-by-project buying is too slow
The opposite extreme — scoping each piece of work, getting a quote, signing a per-engagement contract, then starting the work — is too slow for modern software cadence. Three concrete problems:
- Scope-to-shipped lag. Each new piece of work means a new procurement cycle. By the time the contract is signed, the work is 4-8 weeks behind where it would have been with already-engaged capacity.
- Per-engagement legal overhead. Customer legal reviews each new MSA addendum or new vendor contract. Ten small engagements over a year mean ten legal cycles.
- Per-engagement vendor relationship cost. Each new engagement requires re-establishing context with the vendor — codebase walkthrough, conventions, tooling access, escalation paths. The setup tax compounds.
For customers with multiple smaller engagements over time, project-by-project buying becomes its own kind of expensive — not in dollars per engagement, but in elapsed time and in-house procurement overhead.
What is a VDC Pack?
A VDC Pack is a pre-purchased bundle of Delivery Units that the customer can consume across one or more engagements within a validity window. The customer pays upfront for the pack; consumes DUs as work ships and is accepted; refunds unused DUs at the validity-window end (or rolls them forward by topping up).
The four standard packs:
| Pack | DUs | Price | $/DU | Validity |
|---|---|---|---|---|
| Starter | 10 | $2,000 | $200 | 90 days |
| Small ★ Most Popular | 60 | $10,000 | $167 | 6 months |
| Scale | 300 | $40,000 | $133 | 12 months |
| Enterprise | Custom | Custom | $120-$140 | Custom |
Within the validity window, the customer can consume DUs across multiple engagements without re-signing contracts. The Starter pack ($2K, credit-card checkout) is engineered specifically to bypass procurement — most managers can authorize it on discretionary spend.
How VDC Packs work in practice
Step 1: Purchase the pack
Starter, Small, and Scale packs are self-service — credit-card or invoiced purchase, immediate DU credit to the wallet. Enterprise packs are custom-scoped with MSA, DPA, and dedicated success management.
Step 2: Scope work as it emerges
When a piece of work needs to ship, the customer scopes it with the platform. The Instant Proposal sizes the work in DUs (typically 5-30 DUs per piece of work, with individual stories capped at ~20 DUs). Pre-flight DU estimation shows the customer the count before any work commits.
Step 3: Pod composition and execution
For each engagement consuming DUs from the pack, AiDOOS commissions a pod with the right specialism mix. The pod includes an embedded Delivery Manager who runs the engagement. Pod composition adapts to the work — frontend-heavy for product UI, data-heavy for analytics work, AI-heavy for LLM integration.
Step 4: DU consumption on acceptance
DUs only consume from the wallet when work ships and acceptance criteria are met. Work in progress doesn't consume. Failed-acceptance work doesn't consume. The customer's wallet balance ticks down only as accepted output accumulates.
Step 5: Rollover or refund at validity end
At the validity window end (90 days for Starter, 6 months for Small, 12 months for Scale), unused DUs in the wallet are either refunded at the rate paid (24-48 hours back to original payment, no questions asked) or rolled forward into a new pack via top-up.
Why packs handle volume variance better than retainers
The pack model absorbs the customer's volume variance natively. Three properties:
- Pre-purchased capacity, deploy-when-ready. Buy the pack now; deploy DUs across the validity window as work emerges. No monthly clock running while the customer aligns internal stakeholders or waits for product priorities to crystallize.
- Multi-engagement spreading. A 60-DU Small pack can cover one 60-DU build, or six 10-DU iterations, or any mix in between. The customer's actual consumption pattern flexes within the pack.
- Refundable-on-exit posture. If priorities shift dramatically, unused DUs refund. Compare to a 12-month retainer where the customer is locked in regardless of whether work materializes.
Who should use VDC Packs
Starter pack ($2K / 10 DUs / 90 days)
The "low-friction first engagement" pack. Designed for managers with discretionary spend authority who want to test the model with a small slice of work. Common uses: a single feature build (5-10 DUs), a focused integration (5-8 DUs), a proof-of-concept for a future engagement, a one-off documentation or accessibility audit (3-5 DUs).
Small pack ($10K / 60 DUs / 6 months) — Most Popular
The activation tier. Most customers land here. Designed for product teams running multiple small-to-medium engagements over a quarter or two. Common uses: 2-3 medium product feature builds, ongoing fractional execution across multiple specialisms, a small-to-medium SaaS implementation, a focused modernization spike.
Scale pack ($40K / 300 DUs / 12 months)
Multi-team or sustained-engagement tier. Best per-DU rate in self-serve flow. Common uses: a 6-month product build, sustained engineering acceleration alongside in-house team, a multi-quarter modernization, an Implementation VDC running multiple SaaS implementations.
Enterprise pack (custom)
Strategic relationships with custom DU commitment, MSA, DPA, dedicated success management, and rates at $120-$140/DU. Common uses: multi-year capability engagements, programs requiring custom compliance frameworks, multi-pod transformation programs, SaaS vendors running 20+ implementations per quarter.
How VDC Packs lead naturally to subscriptions
The progression most customers follow:
- Starter pack for the first small piece of work — credit-card checkout, no procurement
- Small pack top-up after the Starter pack's first engagement ships — most customers consume the 10 Starter DUs in 4-8 weeks and top up to 60 DUs as the engagement scales
- Scale pack as engagement volume sustains — typically 4-6 months in, when the customer has consistent multi-DU monthly volume
- Enterprise commitment for sustained programs — typically 9-12 months in, when the customer wants annualized rate guarantees and dedicated success management
This is functionally a subscription, but the customer arrives at it organically rather than committing to monthly billing upfront. Each step is justified by the previous step's results.
VDC Packs vs alternatives
| Procurement Model | Pre-Commitment | Volume Variance Tolerance | Refundability | Speed-to-First-Engagement |
|---|---|---|---|---|
| Monthly retainer | High (12-month commitments common) | Low (paid regardless of usage) | None | Slow (procurement cycle) |
| Project-by-project | Per-engagement | High (only pay per project) | Per-engagement | Slow (per-engagement cycle) |
| Hourly contractor | Low | Mixed (variable hours, sunk minimums) | None for billed hours | Medium |
| VDC Pack | Single pack purchase | High (pack consumes flexibly) | Refundable unused DUs | Fast (Starter is credit-card) |
Example buying journeys
Growth-stage SaaS company
Mid-Series-A SaaS company has growing implementation backlog. Engineering manager orders Starter pack ($2K credit-card) for a single customer-implementation build. Pod ships the implementation in 4 weeks consuming 8 DUs. Engineering manager tops up to Small pack for the next two implementations. By month 6, the company has consumed 50 DUs across 4 implementations and tops up to Scale pack for sustained delivery. Year 2 converts to Enterprise tier with annual DU commitment.
Mid-market enterprise modernization
Mid-market enterprise needs to migrate a Rails 5 monolith to a service architecture. Architect orders Scale pack ($40K) up front based on Instant Proposal sizing of 200 DUs. Pod runs the modernization over 8 months consuming 220 DUs (slightly over estimate; customer adds a top-up of 30 DUs). Migration ships; pack converts to Enterprise tier for ongoing capability work.
SaaS vendor with high implementation volume
SaaS vendor running 20+ customer implementations per quarter goes directly to Enterprise tier with custom DU commitment. The implementation playbook is templated at 60 DUs per mid-market customer onboarding; the SaaS vendor pre-commits 1,500 DUs/quarter at Enterprise rates (below $140/DU). Customer onboardings ship in 2-3 weeks each with predictable DU consumption.
FAQ
What's the smallest engagement I can run?
The Starter pack at 10 DUs is the smallest. Within that, individual stories are typically 3-15 DUs. A focused 3-DU piece of work (e.g., a documentation update or a small accessibility fix) is operationally feasible.
What happens if I overestimate my DU needs?
Unused DUs at validity-window end refund at the rate paid, no questions asked. Or top up before expiry to roll the unused DUs forward into a new pack. There's no penalty for overestimating.
What happens if I underestimate?
Top up at the same tier rate or move to a higher tier with better $/DU economics. Top-ups consolidate the wallet and extend the validity window.
Can I share a pack across multiple business units?
Within reason. Enterprise packs typically support multi-BU consumption with cost-allocation reporting. For Starter / Small / Scale packs, the typical pattern is one pack per buying entity.
How do refunds work?
DUs in the wallet (not allocated to active in-progress work) refund at the rate paid, processed back to the original payment method. The mechanism works because AiDOOS pays $0 talent cost against unconsumed DUs — refunds cost the platform nothing on the unallocated side.
Where to start
If you have a single piece of work in mind, Starter pack ($2K, 10 DUs) is the lowest-friction entry point. If you have multiple smaller engagements over a quarter, Small pack ($10K, 60 DUs) is typically the right starting tier. Schedule a call to walk through your typical work pattern and tier recommendation.
For pricing details, see the pricing page. For the broader DU pricing primer, see Delivery Units and the DU pricing explainer. For terminology, see the AiDOOS glossary.