Agencies coordinate the work. Spar delivers it integrated, end to end.
A boutique agency or senior consultant brings strategic judgment, bespoke research, and a human on the call when results are bad. That work is real, and Spar does not replace it. What Spar replaces is the testing throughput a retainer struggles to staff: it audits every page type continuously, ranks gaps by revenue impact, drafts the hypothesis, generates the variation code, and declares the winner. Many of the best Shopify brands run both.
Human hours vs a continuous engine
An agency rents you senior hours. Spar is a continuous engine that audits every page type, ranks gaps, ships variations, and declares winners. Many brands run both.
- Workflow coverageAgency or consultantAuditIdeaTestMeasureCoverage: Audit covered, Idea covered, Test not covered, Measure coveredSparAuditIdeaTestMeasureCoverage: Audit covered, Idea covered, Test covered, Measure covered
- Operating modelAgency or consultantHuman expertise rented by the hour. Monthly retainer or project-based.SparProductized growth team in software. Audits, ranks, drafts, ships, and declares the winner, continuously.
- ThroughputAgency or consultant1-2+ week turnaround. Hypotheses delivered weekly, audits monthly, reviews quarterly.SparEvery page type of the store audited continuously. Opportunities ranked.
- What gets shippedAgency or consultantRecommendations, hypotheses, decks. Some agencies also build and ship variants. Some bundle execution at higher tiers.SparGenerated variation code, shipped via theme app extension or embed. Winner declared with sequential stats.
- AI depthAgency or consultantDepends on the agency. Output speed is gated by human hours.SparAudits the storefront, ranks gaps, drafts hypotheses, generates variation code, declares the winner.
- Evidence libraryAgency or consultantThe consultant's experience. Varies enormously by who you hire. Knowledge does not compound between engagements unless the agency has internal IP.SparOpinionated rule library that improves every week and applies to every store.
- Cost per findingAgency or consultant$5k-$15k/mo for 10-30 senior hours. Each prioritized finding costs hundreds to low thousands of dollars.SparContinuous coverage at a transparent monthly tier. Per-finding cost orders of magnitude lower.
- Pricing modelAgency or consultantBoutique retainer $5k-$15k/mo plus sometimes performance share. Senior consultant $150-$400/hr or $3k-$8k/mo project-based.SparTransparent monthly tiers, published.
- Strategic brand-level positioning judgment
- Custom qualitative research interviews
- Senior judgment on category-creation problems
- Accountability on the call when results are bad
- Storefront audit run continuously
- Revenue-impact ranked opportunities updated daily
- Testable variation code
- Multiple design mockups
- Ship-without-testing lane for obvious fixes
- Native Shopify theme app extension delivery
- Auto-surfaced GA4 and Clarity observations
- Sequential statistical engine
- Shareable stakeholder-ready CRO reports
- Rule library that improves with every customer
Spar covers every stage.
Agencies own the strategy stages. The ship-and-measure stages are usually work the retainer does not cover.
- 01AuditFind the highest-impact gaps on the storefront.Your agencyHuman-driven, point-in-time. Depth varies by senior availability. Usually 1-2 pages per week.SparRule library scores every page type by evidence and revenue impact, continuously.
- 02IdeationTurn the gap into a testable hypothesis.Your agencySenior strategist writes hypotheses on a weekly or monthly cadence.SparHypothesis drafted from the audit, evidence library, and VoC, ranked by expected lift.
- 03Variation codeBuild the variant that actually ships to traffic.Not in the boxMost agencies recommend; few build and ship variants. Some bundle execution at higher tiers.SparVariation code generated from the audit. You approve before live.
- 04Ship & measureRoll out, wire analytics, watch for flicker and SRM.Not in the boxAgencies hand off to your team or a separate testing platform.SparTheme app extension delivery. GA4 and Clarity wired in. No flicker.
- 05Winning variationDecide what wins and what ships permanently.Your agencyReadouts and decks. Senior judgment on what to ship permanently.SparSequential statistics declare the winner automatically. You review.
Illustrative. Spar's coverage reflects the product surface; the agency owner labels reflect a typical boutique retainer scope, which varies by engagement.
Which one fits the problem in front of you
Pick a CRO agency or consultant if
- You have a brand-positioning or category-creation problem.
- You need custom qualitative research, user interviews or jobs-to-be-done work the rule library cannot run.
- You want senior judgment on edge cases your store presents that no rule library has seen.
- You want a human on the call when results miss.
Pick Spar if
- You have an in-house team to manage CRO.
- You want the cost per finding to be orders of magnitude lower than a retainer.
- You want the testing engine to run while you sleep and improve as the rule library learns.
- You want the variation code and the hypothesis, going beyond recommendations.
Many of the best Shopify brands run both. A senior consultant on retainer for strategic decisions, plus Spar for the continuous testing engine that retainer would otherwise have to staff.
Questions buyers ask
Retainer, or engine
See the example site live and get what a strong agency would open an engagement with: ranked opportunities, the evidence behind each, and the first variation ready to test.