Building your waterfall internally
To secure good pricing, you commit to fixed volumes with each provider, which leads to underutilization and wasted spend.
A dedicated engineering team is needed to manage 20+ different APIs, each with its own format, error model, and rate limits.
Volume commits don't refund. Unused credits at the end of every contract evaporate, quarter after quarter.
API failures and provider updates silently drop accuracy. You pay for the request, your customer pays for the bounce.
GDPR, CCPA, opt-outs: the legal surface area grows every quarter. Each new region is a new compliance project.
One provider goes down, your customer sees an error. No fallback, no graceful degradation, no on-call rotation built for it.
Provider quality drifts. Without continuous benchmarking, the ranking you set 6 months ago is already wrong.
Without deduplication across providers, the same record gets billed twice (or three times) on the same lookup.

