Use AppExchange apps when a well-reviewed, mature solution already exists for a common, non-differentiating business need — and building it custom would consume time and effort better spent on requirements that are actually unique to your business. AppExchange is at its best for commodity capabilities (e-signature, mass email, data quality, document generation, calendar integration) and at its worst when the requirement is genuinely strategic or when integration depth matters more than time-to-value.
When to buy (use AppExchange)
- Commodity functionality. E-signature, electronic forms, mass email, address validation, time tracking — solved problems, no business advantage in re-solving.
- You need speed. A go-live deadline in weeks rules out custom development for anything non-trivial.
- Compliance burden. SOC 2-certified mass-email engines, GDPR-compliant data subject request handlers — buying a vetted solution is cheaper than getting custom code certified.
- Cross-system integration is already built. Apps like DocuSign or Adobe Sign already have battle-tested OAuth, webhook handling, and error recovery. Re-building costs more than buying.
- The vendor’s app gets upgrades you don’t have to maintain. Three releases a year on Salesforce + occasional vendor enhancements = features arrive without your team doing the work.
When to build
- It’s your differentiator. If the requirement is what makes your business unique — your proprietary credit-scoring algorithm, your custom lead-qualification logic — build it, control it, evolve it.
- No good app exists. Search AppExchange first; if nothing meets the requirement or every option has 2-star reviews, building is the answer.
- Cost at scale. Most AppExchange apps price per user. At 5,000+ users, a custom build may pay back in a year.
- Integration friction. If the vendor’s app doesn’t expose the hooks you need (custom triggers, custom UI extension points), customizing around it is harder than building from scratch.
- Security or data residency. If the app sends your data to the vendor’s servers and your compliance regime disallows that, you can’t use it.
A decision rubric
A quick framework for the build-vs-buy conversation:
| Question | Lean buy if… | Lean build if… |
|---|---|---|
| Is this a differentiator? | No | Yes |
| Is there a mature option with strong reviews? | Yes | No |
| Time pressure? | High | Low |
| Per-user cost vs build cost over 3 years? | Buy is cheaper | Build is cheaper |
| Do we control the data flow? | Vendor’s hosting is fine | We need data to stay in our org |
| Do we need deep customization the vendor doesn’t allow? | No | Yes |
Vetting checklist before installing
Even when buying, validate:
- Reviews and listing age — established apps with hundreds of positive reviews are usually safe; brand-new apps deserve more scrutiny.
- Security review status — Salesforce-reviewed apps display a security review badge.
- Listing partner type — ISV Partners with the Salesforce partner program are vetted.
- Trial availability — install in a sandbox first; check the namespace, custom objects, automation, and whether it interferes with your existing customizations.
- Support model and SLAs — read the support tier you’re paying for.
- Uninstall path — what happens to data when you remove the package? Some apps leak orphaned records.
Quick interview answer
“Use AppExchange when the requirement is commodity, non-differentiating functionality — e-signature, data quality, document generation, mass email — and a mature, well-reviewed app exists. Don’t use it when the requirement is genuinely strategic to your business, when no good app exists, when costs at scale exceed a custom build, or when integration depth requires more flexibility than the vendor allows.”
Verified against: Salesforce Help — AppExchange and AppExchange. Last reviewed 2026-05-17.