Privacy
This site is run by Useful Build, a studio operated by Karko AI Inc., 1207 Delaware Ave #412, Wilmington, DE 19806, USA. Karko AI Inc. is the data controller for this site. We collect very little, and this page says exactly what.
What we collect
Analytics. We use PostHog US Cloud to understand page views, booking and email clicks, browser and device information, approximate country, Web Vitals and JavaScript errors. We also use privacy-masked session replay to see where the site is confusing. Inputs are masked, client IP addresses are discarded and we don't create account identities or advertising profiles.
Product analytics. PostHog records page views and conversion events such as booking clicks. We do not run a live homepage headline experiment. Booking-form answers remain with Cal.com and are not sent to PostHog.
Email and booking. When you write to hello@usefulbuild.com or book a call, we keep that correspondence so we can reply and work with you.
What we don't do
We don't sell your data. We don't run ad networks or cross-site tracking. We don't train AI models on anything you send us.
Hosting
The site is served by Cloudflare, which processes technical request data (like IP addresses) to deliver the site and protect it from abuse, acting as our infrastructure provider.
Who we share data with
Service providers that run parts of this site for us: PostHog (analytics), Cloudflare (hosting) and Cal.com (booking). Each processes data only to provide its service. Beyond that, we share personal data only with professional advisors such as lawyers and accountants, with authorities when the law requires it, or with a buyer if our business is ever sold or merged. We never sell it.
Legal bases (GDPR)
If you're in the European Economic Area or the UK, we rely on: legitimate interests for analytics and site security (understanding and protecting a low-traffic business site), steps before or under a contract when you email us or book a call, and legal obligations for records we're required to keep. We don't use consent-based tracking, because there is none.
How long we keep things
PostHog retains analytics events for seven years and session recordings for 30 days in the current project. Email correspondence is kept while we're in contact or as the law requires. When we no longer need personal data, we delete it or anonymize it.
Analytics choice
This analytics setup is cookieless. PostHog runs with in-memory persistence: nothing is stored on your device and no identifier survives your visit, which is why the site runs without a consent banner. We will review this approach if our setup, traffic mix or legal obligations change. You can block analytics with a tracker-blocking extension and the site will continue to work.
Where your data goes
We're a US company, so data collected here is processed in the United States, where privacy law differs from European law. Where European data reaches a US provider, it's covered by recognized safeguards: PostHog is certified under the EU-US Data Privacy Framework and provides a Data Processing Addendum, and our providers offer standard contractual clauses. Email us for details on any specific transfer.
Security
We use technical and organizational safeguards to protect the little we collect, and we collect little precisely so there's little to protect. No internet service can guarantee perfect security.
Your rights
If you're in the European Economic Area or the UK, you can ask for access to your personal data, correction, deletion, restriction of processing, a portable copy, and you can object to processing based on legitimate interests. Where we ever rely on consent, you can withdraw it. You can also complain to the data protection authority where you live; in the UK that's the Information Commissioner's Office (ico.org.uk).
If you live in a US state with a privacy law (like the CCPA), you can ask what we hold, and ask us to correct or delete it. We don't sell or share personal information for targeted advertising, and we don't profile anyone in ways that produce legal effects. If we decline a request, you can appeal by replying to our answer.
For any of this, email hello@usefulbuild.com and we'll sort it out. We may ask you to confirm your identity first.
Children
This site is for businesses and isn't directed at children. We don't knowingly collect data from anyone under 16.
Changes
If this policy changes, the new version appears here with a new date.
Contact
Karko AI Inc., 1207 Delaware Ave #412, Wilmington, DE 19806, USA · hello@usefulbuild.com
Effective August 29, 2026.