B2B data
B2B marketing data: first party, bought lists, and decay
B2B marketing data is the information you use to find and talk to accounts: people, firms, intent, and engagement. First-party data you collected with consent ages better than a bought list, but both decay. Job changes and domain churn are the tax.

First party is the data you already earned
Form fills, product usage, support tickets, webinar attendance, and contractual contacts are first party. You know why you have them, and you can usually email them under a lawful basis you can explain. This is the data that should sit in the CRM as the source of truth for "who we may contact." Enrichment can add firmographics on top. It should not replace the fact of the relationship.
Titles and emails rot. A bought file is a photograph, not a live list.
Bought lists and how fast they rot
A vendor file of emails and titles is a snapshot. People change jobs. Inboxes bounce. GDPR and similar rules still apply even if the vendor smiled on a sales call. Use bought data to prioritize research and to find accounts, then confirm the person and the permission path before you run a sequence. A list that was "accurate" last quarter is a bounce factory this quarter.
The ICO's guidance for organizations is a practical place to start if you sell into the UK or EU. You do not need to become a lawyer. You do need a story for why this person is in your send.
Decay is an operating cost
Plan for bounce handling, job-change suppression, and a quarterly recrawl of your ICP accounts. Marketing teams that treat the database as a lake they filled once will watch deliverability and reply rates fall and blame copy. Copy cannot fix a list of people who left the company.
Intent and other rented signals
Third-party intent can hint that a topic is being researched. It cannot tell you the committee is ready. Treat it as a reason to look at an account this week, not as a lead. Combine it with first-party behavior when you have it. If you only have the vendor's score, you have a maybe.
Common questions
Is enrichment the same as buying a list?
No. Enrichment adds fields to records you already have (size, industry, tech). A list purchase adds records you did not have. The compliance and quality problems are related but not identical. Enrichment of a bad email still leaves you with a bad email.
How often should we reclean B2B data?
Bounces and unsubscribes continuously. Job titles and account fit at least quarterly for active outbound segments. Annual "we will get to hygiene" is how you wake up with a CRM nobody trusts.
Related
Prefer markdown? B2B marketing data: first party, bought lists, and decay.md