Amazon agencies typically charge $3K–$15K/month for management retainers and $8K–$20K/month for full-service engagements that bundle ads, creative, catalog ops, and case management. Some agencies pair the retainer with a percentage of ad spend (2–5%) or a percentage of marketplace revenue (3–8%). Performance-only deals that charge 15–25% of ad spend with no retainer exist but are rare. Most agencies don’t take that risk below $500K annual Amazon revenue.

You own your Amazon ads account, not the agency. A reputable agency operates with user permissions inside YOUR Seller Central or Vendor Central login, never a parallel account under their banner. If an agency insists on running ads through their own account, walk away. When the contract ends with an agency that owns the account, so does your PPC history, keyword learning, and account-level eligibility. Nectar never runs client ads out of its own account.

Hire an Amazon agency above $250K/month in revenue, consider it between $50K and $250K/month if you don’t already have a dedicated internal marketer, and stay DIY below $50K/month where the learning curve is cheap and the upside of expertise is modest. Between $50K and $250K/month, PPC optimization becomes a second job. Most solo founders break here. Above $250K/month, the opportunity cost of your time plus the compounding damage of a poorly run account usually makes hiring an agency a cheaper decision than staying in-house.

Four non-negotiables: (1) all ad accounts operate under your login credentials, not the agency's; (2) all raw data — AMC queries, campaign builds, search-term reports — is yours, exportable on 30-day notice in usable formats; (3) creative IP (photography, video, A+ Content) transfers to you on payment with clear commercial usage rights; (4) a no-solicit or neutral-zone clause that prevents the agency from pitching direct competitors during the engagement using your performance data. Agencies that push back on any of these are optimizing for their leverage, not yours.

Run a structured diagnostic on the three levers an agency actually controls: ad efficiency (campaign structure, negative keyword hygiene, bid discipline), catalog optimization (listing quality, A+ Content depth, keyword coverage in titles and bullets), and reporting cadence (what gets proactively flagged versus what's reactive). Pull 90 days of Sponsored Ads reports and score against category benchmarks. A good agency shows continuous experimentation signal in the data; a coasting one shows flat campaign structures untouched for months. You don't need an RFP to know whether your agency is coasting. You need two hours with your data and a category benchmark.

In the first 30 days with a new Amazon agency, expect discovery, audit, and access handoff, not live campaign changes. Days 31–60 bring foundation changes (campaign restructures, listing optimization, creative briefs). Days 61–90 produce the first real performance signal and a rolling 90-day plan. A good agency spends days 1–30 auditing your account, documenting baseline performance, and identifying quick-win opportunities. You should expect very little execution in the first two weeks, reporting and diagnostic calls instead. Days 61–90 produce initial performance signal from the foundation changes, first strategic recommendations based on actual data, and alignment on a rolling 90-day plan for the next quarter. If an agency is “running campaigns” in week 1, they’re either skipping the audit or rebadging work they did on another account.

To switch marketing agencies without losing account history, lock down three non-negotiables before giving notice: confirm Amazon Ads, Seller Central, Google, Meta, and Klaviyo accounts are registered under YOUR credentials (not the agency’s), export all creative assets in usable formats with transfer documentation, and pull 90 days of performance reports from every platform. If accounts are still under the agency’s credentials, get the ownership transferred BEFORE giving notice. Transition typically takes 30–60 days. Plan around it. Never fire an agency on a Friday; always time transitions mid-cycle (ideally mid-month) to give the incoming team runway.