In short
\nThe Mews Booking Engine already sends a solid set of events to Google Tag Manager. This free kit builds on them: it adds the stay data, net revenue and stable event names that paid media bidding and reporting rely on, without leaving GTM.
\nMews gives hotels a solid booking engine and a native Google Tag Manager integration. What it does not give you is a dataLayer your tags can use as it comes. The events are there, but they are named and shaped the Mews way, they miss the fields paid media needs, and Mews provides them “as is”, with no customisation.
We built a dataLayer kit that fixes this inside GTM, without asking Mews for anything. It is free, and you can get it at the end of this post.
\n\n// pushed by the Normalizer, after Mews' purchase\ndataLayer.push({\n event: 'hirundo_purchase',\n context: {\n property_name: 'Example Hotel',\n funnel_step: 'confirmation'\n },\n stay: {\n check_in_date: '2026-10-31',\n nights: 2, lead_time_days: 29\n },\n ecommerce: {\n value: 160, value_net: 142.86,\n value_room: 160, value_extras: 0,\n currency: 'EUR'\n }\n});The Mews Booking Engine pushes 19 events to the dataLayer: 12 page events prefixed ga4_ (calendar loaded, rates loaded, booking created and so on) and 7 GA4 e-commerce events, from view_item_list to purchase.
That is a good base. Four gaps show up as soon as you plug real tags into it:
You cannot change what Mews pushes. You can change what your tags read.
The kit adds one tag to your GTM container, the Normalizer. It listens to each native Mews event and pushes a second event next to it, prefixed hirundo_, in a schema that stays the same at every step of the funnel. GA4, Google Ads and Meta read only the hirundo_ events. If Mews changes something, you update one mapping in one tag.
Every event carries the same four objects: context, stay, ecommerce and booking. Your tags read one structure at every step of the funnel.
Nights and lead time, calculated on every step instead of only at the purchase.
Mews has no search event. The kit derives one from the room list, and flags the searches that returned no available room.
Mews consent is mapped to Consent Mode v2, and a reloaded confirmation page never sends a second purchase.
The full structure of a normalised event, with a complete purchase example to compare against GTM Preview.
Each native Mews event, its normalised equivalent and the GA4 event name to send. Sixteen events in total.
Ready to paste into a Custom HTML tag. It listens to Mews and pushes the clean event next to each native one.
The variables, triggers and tags to create, the Mews Operations settings to switch on, and the tests to run before you publish.
Net value for ad platforms, gross for analytics. GA4 receives the tax-inclusive value, which matches what the hotel reports. Google Ads and Meta receive the net value, so a campaign in a market with 10% VAT is judged on the same basis as one with 20%.
One primary conversion. hirundo_purchase is the only conversion that carries a value and drives bidding. Add to cart and begin checkout are secondary conversions, there to help the algorithms learn.
Multi-property from day one. Every event carries the property ID. A single lookup table in GTM routes each hotel to its own GA4 property, Google Ads conversion and Hotel Center ID, with a chain default for the steps before a guest picks a hotel.
mews.com to the GA4 cross-domain settings.One limit to know about: this kit covers the Booking Engine. The Guest Journey (online check-in, Kiosk, upsells after booking, cancellations) has no dataLayer. Measuring it means working server-side from the Mews PMS, which is a separate project.
Running a hotel group on Mews and want this set up, or extended to the Guest Journey and to offline conversions? Book a call with Hirundo.
\n\n\n", "image": "https://hirundo.global/media/posts/16/mews-datalayer.png", "author": { "name": "Hirundo Team" }, "tags": [ "Analytics" ], "date_published": "2026-10-02T10:27:07+02:00", "date_modified": "2026-10-02T15:34:32+02:00" }, { "id": "https://hirundo.global/scaling-dtc-brand-new-markets/", "url": "https://hirundo.global/scaling-dtc-brand-new-markets/", "title": "Scaling a DTC brand into 12 new markets", "summary": "How a disciplined testing framework tripled ROAS in six months A fast-growing DTC brand had proven demand at home but no repeatable way to enter new markets. Every launch felt…", "content_html": "\n\n How a disciplined testing framework tripled ROAS in six months\n
\n\n\n A fast-growing DTC brand had proven demand at home but no repeatable way to enter new markets. Every launch felt like starting from scratch, and spend outran returns.\n
\n\n\n We built a market-by-market testing framework: a small controlled budget per market, one variable changed at a time, and a single metric of truth: contribution margin. We scaled winners and cut losers fast.\n
\n\n\n Within six months the brand was live in 12 new markets, return on ad spend had tripled versus the old approach, and the in-house team had a launch playbook they could run themselves.\n
", "author": { "name": "Hirundo Team" }, "tags": [ "Paid media" ], "date_published": "2026-07-08T18:46:15+02:00", "date_modified": "2026-07-22T20:48:27+02:00" }, { "id": "https://hirundo.global/migration-playbook-cross-border-growth/", "url": "https://hirundo.global/migration-playbook-cross-border-growth/", "title": "The migration checklist for cross-border growth", "summary": "Expanding into a new market rarely fails on media budget, it fails on the translation of intent. These are the five principles we use to make campaigns travel. Localise the…", "content_html": "\n\n Expanding into a new market rarely fails on media budget, it fails on the translation of intent. These are the five principles we use to make campaigns travel.\n
\n\n\n Most creative budgets are spent proving what we already suspected. A lean testing framework finds winners faster, and for less.\n
\n\n\n Every test should answer a question: 'does social proof beat urgency?' Even a loser teaches you something reusable.\n
\n\n\n Hook, format, or offer: change one, hold the rest. Bundled changes give you a result you can't explain or repeat.\n
\n\n\n Equal budget, same audience, enough time to reach significance. Cheap tests that don't bring conclusions are an expensive waste.\n
\n\n\n Cut clear losers early, but let winners prove themselves before you pour in cash. Early winners regress more often than anyone would like.\n
", "author": { "name": "Hirundo Team" }, "tags": [ "Paid media" ], "date_published": "2026-07-08T13:23:12+02:00", "date_modified": "2026-07-22T20:48:40+02:00" }, { "id": "https://hirundo.global/attribution-you-can-actually-act-on/", "url": "https://hirundo.global/attribution-you-can-actually-act-on/", "title": "Attribution you can actually act on", "summary": "Perfect attribution doesn't exist. Useful attribution does, the kind that tells you what to do on Monday morning. The value isn't in the model's accuracy, it's in applying the same…", "content_html": "\n\n Perfect attribution doesn't exist. Useful attribution does, the kind that tells you what to do on Monday morning.\n
\n\n\n The value isn't in the model's accuracy, it's in applying the same lens consistently so trends are comparable over time.\n
\n\n\n Server-side tracking and clean event naming beat any clever model sitting on top of messy data.\n
\n\n\n Geo-tests and holdouts answer the only question that matters: what would have happened anyway?\n
\n\n\n If a dashboard number wouldn't change a budget or a bid, stop reporting it. Measurement exists to drive action.\n
", "image": "https://hirundo.global/media/posts/7/pexels-reinis-bruzitis-2153679369-35828991.jpg", "author": { "name": "Hirundo Team" }, "tags": [ "Analytics" ], "date_published": "2026-07-08T13:22:12+02:00", "date_modified": "2026-07-22T20:48:53+02:00" } ] }