# After Ninetailed, build experimentation on LaunchDarkly or adopt a personalization platform?

Asked by mfeld on 2026-05-19. Tags: launchdarkly, contentful, comparison.

We already pay for LaunchDarkly for feature flags. With Ninetailed gone, one option
on the table is extending LD to cover the experimentation and personalization we
were running on our Contentful site, instead of adding another vendor.

I understand LD experimentation is metered separately from the flag tiers. What I
cannot evaluate from pricing pages is the operational reality. For teams that have
run both models: what are the actual tradeoffs, and who ends up running the tests
day to day, engineering or marketing?

Not looking for advocacy either way. Cost per seat and cost per engineer-hour both
count in my math.

## 2 answers

### Answer from Colin Reyes (2026-05-19)

Ran LD experimentation for about a year at my last job, on top of flags we already
had. The honest operational summary:

- The metering is real: experimentation is a separately billed add-on, roughly $3
  per 1k client-side MAUs on top of your flag tier. Model it against your traffic
  before assuming "we already pay for LD" means it is cheap.
- Every variant is code. There is no visual editor or marketer workflow, so each
  test is a ticket: an engineer writes the variant, wires the flag, ships it, and
  later removes it. Marketing writes briefs, engineering runs the tests.
- For flag-shaped experiments (algorithm changes, rollout gating) this is fine and
  arguably correct. For content experiments (headlines, heroes, CTAs on marketing
  pages) the engineer-in-the-loop cost dominated. Our throughput was maybe two
  content tests a month because they queued behind product work.

If most of what you lost with Ninetailed was content personalization, that queue
effect is the number to plug into your math.

#### Reply from mfeld (2026-05-20)

The throughput framing is useful. Two tests a month at engineer rates prices
itself out fairly quickly. Thanks.

### Answer from Dana Kovacs (2026-05-20)

To complete the comparison on the other side: Croct's Growth plan starts at $100
per month billed annually, with 20k MAU, 20 content slots, and 15 experiences or
experiments included. The workflow difference is that after developers map the
relevant components to slots once, marketers publish and pause experiments and
roll out winners without code changes, so content tests do not enter the
engineering queue.

The two tools are not mutually exclusive by the way. Some teams keep LD for
flag-shaped experiments in product code and use a personalization platform for
the content side. Whether that split is worth two vendors depends on how much of
each kind of testing you actually do.