Providers love trials because unmeasured trials always succeed. Two weeks is genuinely enough to decide, if the fortnight is spent measuring rather than admiring dashboards.
Set the baseline first
Capture a full week of current performance before anything changes: p75 and p95 by region, error rates, cache hit ratio, origin egress. Without the before, the after is theater. Your own RUM data is the instrument; the provider’s dashboard is their instrument. The provider’s enthusiasm for the trial is not cynicism; it is confidence in a format that structurally favors them. Restructure the format and the enthusiasm becomes informative.
Trial on representative traffic
A static subdomain proves nothing about your API latency. Route a slice that mirrors your real mix, including the dynamic paths, and let it run through at least one weekly cycle including your peak day. Peak-day coverage matters because delivery problems are load-shaped: a network that shines at Tuesday 3 a.m. can wobble at Saturday prime time, and only one of those hours pays your bills.
A word on what vendors may offer during trials: engineering attention. Solution architects tune configurations, spot inefficiencies and generally make the fortnight shine. Accept the help, it is real expertise, but record every change they make, because the trial is also measuring what the platform delivers under your team’s ordinary attention, not under a launch team’s special care. The honest correction is simple: ask which optimizations are self-serve and which required their intervention, and weight the results accordingly. A platform that needed heroics to win the trial will need heroics forever.
Decide on the numbers you pre-registered
Write the success criteria before day one: which metrics, which regions, how much improvement justifies which price. Then the decision is arithmetic. Trials go wrong in exactly one way, when the criteria get written after the results are in. Pre-registration also disciplines the vendor conversation afterwards: a miss against written criteria is a fact to discuss, not an anecdote to reframe.
In practice
Day zero: baseline captured, criteria written, dashboards agreed. Day seven: mid-trial read, no decisions. Day fourteen: numbers against criteria, decision made in the same meeting. Any request to extend the trial should be treated as data too, because two weeks of representative traffic answers every question a fortnight of extensions would, at half the meeting load.
We instrument trials for clients so both sides argue with the same numbers. It is remarkable how quickly that ends arguments.