Privacy Policy

Last updated: October 28, 2026

This policy explains what information Mold HQ collects when you use moldheadquarters.com and The Practical Guide to Mold & Moisture, how we use it, and the choices you have.

What we collect

• Purchase information. When you buy the guidebook, Stripe and Link process your payment. We receive your email address, name, billing ZIP code and country, and purchase details. We never see or store your full card number.
• Checkout email. You enter your email in Stripe's checkout form. We use it for your receipt, to email you your PDF copy of the guide (the PDF shows your email address and order number on each page), and so you can sign in to the guide on other devices. If your guide access comes with a Mold HQ test kit, our kit store (kits.moldheadquarters.com) tells us your order email and whether the order is still active, so we can sign you in. We don't ask for your email before payment. If you entered your email in an earlier version of our checkout and didn't buy, it is kept with the ad label described below and the date for up to 180 days, then deleted.
• Access cookie and devices. When you sign in, we set a cookie in your browser so you can open the guidebook. To keep each purchase signed in on one device at a time, we store a random ID for each signed-in device, the time it signed in, and its browser type. The cookie is needed for the guide to work and contains no advertising or tracking data.
• Checklist progress. Items you check off in the guide are saved only in your own browser. We don't receive them.
• Basic technical data. Our hosting provider, Cloudflare, processes standard information like IP address and browser type to deliver and secure the site. To prevent abuse of sign-in and checkout, we keep a one-way scrambled version of your IP address for up to an hour.
• Site analytics. We use Cloudflare Web Analytics to count visits and see which pages people open, where visitors come from (for example, an ad or a link), and which countries they visit from. It does not use cookies, does not track you across other sites, and does not build a profile of you.
• Visit and button counts. When you open and use the public pages, your browser sends us short anonymous messages (when a page loads, when you tap one of the counted buttons, and when you leave) that add to running totals by date: that a visit happened, whether you opened the guide preview and roughly how long you spent in it, which parts of the preview you looked at, whether you opened the contents, whether you tapped Explore the Guide or Get the Guide, and which checkout steps you reached, and the ad label described below. We don't store your IP address, name, email, or a cookie with those counts.
• Which link brought you here. If you arrive from an ad or a tagged link, we keep a short label (for example, the name of the ad) in your browser for that visit. If you buy the guidebook, we attach it, and the number of preview pages you looked at, to the purchase so we can see which ads and pages work. It contains no personal information and is cleared when you close the tab.
• Messages. If you email us, we keep your message and email address so we can respond.

The guide's sign-in cookie is not used for advertising. See "Advertising and your choices" below for the advertising tags on our public pages.

How we use it

We use your information to give you access to the guide, help you restore access, respond to you, and keep the site secure. We don't sell or rent your personal information. We do use advertising tags on our public pages, described below.

Advertising and your choices

We advertise on Meta (Facebook and Instagram), Google, TikTok, and ChatGPT (OpenAI). To measure which ads lead to visits and purchases, and to show our ads to people who visited, the public pages of this site (the home page with the guide preview, and the chapter preview pages) load a Meta pixel, a Google tag, a TikTok pixel, and an OpenAI pixel. These tags set or read cookies and send Meta, Google, TikTok, and OpenAI information such as the page you viewed, your browser and device details, your IP address, whether you opened the guide preview, whether you started checkout, and the product and its price. To help match these events, the Meta, TikTok, and OpenAI pixels also send a random visitor ID that we set in a cookie (mhq_vid), hashed (scrambled). When you arrive from a Facebook or Instagram ad, our server also saves Meta's click ID from the link in a cookie (_fbc), when you arrive from a TikTok ad, TikTok's click ID (mhq_ttclid), and when you arrive from an ad in ChatGPT, OpenAI's ad reference from the link (mhq_oppref). OpenAI's pixel also sets its own cookies (__oppref with the same reference, and __obref, a random browser ID). The visitor ID and __obref last up to a year, the click IDs up to 90 days, and the ChatGPT ad reference 30 days, and none of them is set if you've opted out. After a purchase, the page that opens the guide sends one purchase event with the purchase amount, and no information about which chapters you read. We don't load these tags in the purchased guide, apart from that one purchase event.

Under California and some other state laws, this may count as "sharing" personal information for cross-context behavioral advertising. You can opt out at any time with the button below. Your choice is saved in this browser, and in a cookie (mhq_ads) so our server follows it too. We also treat the Global Privacy Control signal from your browser as an opt-out, and the tags don't load for visitors who send it.

You enter your email in Stripe's checkout, which the advertising tags can't see. After a purchase, our server may send Meta, TikTok, and OpenAI a hashed (scrambled) copy of your checkout email with the purchase event, as described below, so they can match the purchase to an ad. If you entered your email in an earlier version of our checkout and didn't finish, we may have added it to an advertising audience on Meta, uploaded as a list that Meta hashes. None of this happens if you've opted out here or your browser sends Global Privacy Control.

We may also send the checkout and purchase events to Meta directly from our server (Meta's Conversions API), with the same information the pixel sends: the event, the product and price, your IP address and browser details, Meta's own cookie IDs (including the ad click ID), and the random visitor ID (hashed). For purchases, it also includes hashed (scrambled) copies of your email and, when Stripe's checkout collected them, your name, ZIP code, and country. This follows the same opt-out.

We may also send the checkout and purchase events to TikTok directly from our server (TikTok's Events API), with the event, the product and price, your IP address and browser details, TikTok's own cookie ID and click ID, the random visitor ID (hashed), and, for purchases, a hashed copy of your checkout email. This follows the same opt-out.

We may also send the checkout and purchase events to OpenAI directly from our server (OpenAI's Conversions API), with the event, the product and price, your IP address and browser details, OpenAI's ad reference and browser ID cookies, the random visitor ID (hashed), and, for purchases, a hashed copy of your checkout email. OpenAI uses this to measure its ads in ChatGPT. This follows the same opt-out.

You can also manage ad settings directly in your Meta, Google, TikTok, and OpenAI accounts.

Who we share it with

• Stripe and Link process payments under their own privacy policies.
• Cloudflare hosts the site and routes incoming email to our support address. Outgoing email (your PDF and sign-in links) is sent through Resend.
• Meta, Google, TikTok, and OpenAI receive the advertising tag data described above, unless you opt out. Meta, TikTok, and OpenAI may also receive a hashed copy of your checkout email with a purchase, and Meta a hashed copy of your name, ZIP code, and country, as described above.
• Google Fonts serves the site's fonts, so your browser requests them from Google, which receives your IP address and browser details.
• Resend delivers the sign-in links and the PDF copy we email to you.
• Other websites. When you click a link to another website, that site may set its own cookies under its own policy.
• Legal requirements. We may disclose information if required by law.

How long we keep it

We keep purchase records for as long as needed to provide access to the guide and to meet tax and accounting requirements. Checkout emails from purchases that weren't finished are deleted after 180 days, or sooner if you ask.

Your choices and rights

You can ask to see, correct, or delete the personal information we have about you by emailing [email protected]. We'll respond within 30 days. You can clear the access cookie and saved checklist progress at any time by clearing your browser data. If you're a California resident, you have the right to know what personal information we collect and how it's used, and you can opt out of the sharing of your information for advertising at any time using the button in "Advertising and your choices." We don't sell your personal information for money.

Do Not Track and Global Privacy Control

We honor the Global Privacy Control signal as an opt-out of advertising tags. Because there is no common standard for the older Do Not Track signal, we don't respond to it.

Children

This site is not intended for children under 13, and we don't knowingly collect their information.

Changes

We may update this policy and will change the date above when we do. Significant changes will be noted on this page.

Contact

[email protected]

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