Cookie

A B2B SaaS company used first-party cookies to personalise their website experience. First-time visitors saw a 'Getting Started' page with educational content. If the same visitor returned (detected via cookie) within 30 days, they saw a 'Compare Pricing' page instead. Returning visitors from target accounts saw custom homepage messaging about industry-specific use cases. This personalisation increased time on site by 40% compared to a control group without personalisation.

For B2B growth teams, cookies are how you track visitors across your website without requiring them to log in or identify themselves. Without cookies, you couldn't tell whether the 100 people who visited your pricing page yesterday included repeat visitors or entirely new prospects.

Cookies enable personalisation at scale. You can use cookie data to show different website content to different visitor segments: new visitors see educational content, returning visitors see case studies and pricing, and logged-in users see custom dashboards or personalised recommendations.

However, cookie regulations are changing rapidly. Privacy regulations like GDPR (Europe), CCPA (California), and others restrict how you can set and use cookies. Many organisations are moving toward cookieless solutions and first-party data strategies. Understanding cookies and their limitations is essential as the landscape evolves.

An enterprise software company used ABM technology to identify when employees from target accounts visited their website via cookie and IP tracking. When someone from a target account visited, they saw different ads on external websites showing that company's use case. This coordinated approach increased conversation rates for target accounts by 60% compared to non-target accounts.

A cookie is a small text file a website asks your browser to save on your device. The next time you visit, your browser hands that file back, so the site can recognise you, remember your settings, and pick up where you left off. Without cookies, every single visit would look like a brand-new stranger walking in the door.

The mechanics are simple. A site sends your browser a tiny file (usually under 4KB) holding something like a visitor ID, a preference, or a record of what you did last time. Your browser stores it and sends it back on the next visit. That round-trip is the whole trick behind 'staying logged in', a half-filled cart that's still there tomorrow, and analytics that can tell a returning prospect from a fresh one.

The distinctions that actually matter for B2B:

• First-party cookies are set by the site you're actually on. They power logins, preferences, and your own analytics. These are the ones you can rely on.
• Third-party cookies are set by another domain (usually ad networks) to follow you across sites. Browsers are killing these off, so don't build anything important on them.
• Session cookies vanish when you close the browser; persistent cookies hang around for days, months, or years.

Why it matters

Cookies are how you make sense of traffic before anyone tells you who they are. Say you're running Microsoft Clarity on your pricing page: the first-party cookie it sets is what lets it tell you that 30 of yesterday's 100 visitors were repeat lookers circling the price, not 100 cold first-timers. That distinction changes how you read the number entirely.

They also let you personalise without forcing a login. Say you're tagging visitors with a cookie through Google Tag Manager: a first-timer sees your 'start here' explainer, while a returning visitor the cookie recognises drops straight onto a case-study or pricing page. Same site, two different journeys, no signup wall.

The catch is that the ground keeps shifting. GDPR, CCPA and friends now dictate which cookies you may set and when, third-party cookies are being phased out, and the smart money is moving to first-party data. Knowing what cookies can and can't do is no longer optional.

How to apply it

Get consent right first. Say you're serving European traffic and need a banner that genuinely blocks non-essential cookies until someone agrees: a tool like Cookiebot scans your site, classifies each cookie, and won't fire the marketing ones until the visitor opts in. Wire its consent signal back into Google Tag Manager so your analytics and ad tags genuinely stay off when someone says no, rather than firing anyway behind a banner that's pure theatre.

For account-based work, lean on first-party signals rather than dying third-party ones. Say you're running Leadinfo: it ties its first-party cookie to company-level IP data so that when someone from a target account lands on your site, you see the company, the pages they read, and how often they come back, and your sales team gets a nudge while the interest is still warm.

The rule underneath all of it: if a visitor opts out of marketing cookies, honour it. Don't set them anyway. A consent banner you ignore is a liability, not a safeguard.

A consulting firm used cookies and analytics to track customer engagement after sale. They identified when existing customers hadn't visited their knowledge base or customer portal for 30 days, signalling potential at-risk relationships. The customer success team proactively reached out to these accounts, preventing churn and increasing upsell opportunities.

If you use Google Analytics or similar tools, understand that your analytics is powered by cookies. Your analytics vendor sets first-party cookies on your domain that track visitor behaviour. Ensure you have a clear privacy policy explaining that you use cookies for analytics and personalisation.

For account-based marketing, consider implementing first-party cookie tracking to identify when employees from target accounts visit your website. Tools like 6sense, Terminus, and similar ABM platforms use IP tracking and cookie technology to identify high-value accounts visiting your site, alerting your sales team.

Be aware of cookie consent requirements. In many jurisdictions, you must obtain explicit consent before setting non-essential cookies. Implement a cookie consent banner that explains what cookies you use and why. Respect user choices: if someone opts out of marketing cookies, don't set them.