Paid ads for SaaS and B2B: run acquisition on CAC payback

Ads for SaaS end in a billing system, not on a thank-you page. The platforms count clicks and the conversions their pixel or tag saw, while the trial converts two weeks later and the annual plan is paid in Stripe. Adrails records the trial, the sign-up and the purchase from your own server, credits each one to the campaign and ad that brought the visitor, and sends the signed events back to Meta Ads and, once your workspace can connect it, Google Ads.

A campaign's Tracking tab then shows which ads brought real customers and what those customers are worth in Stripe or RevenueCat: matched customers, lifetime spend or monthly revenue, average customer value and active subscriptions, by ad. Meta and Google Ads remain the source of their own conversions and ROAS, and the matching counts only the journeys Adrails can identify.

• Record trial_started, signup, lead and purchase events from your server
• Read customer value by ad from Stripe or RevenueCat in the Tracking tab
• Keep the platform's ROAS and your billing figures side by side, never merged

In David Skok's SaaS Metrics 2.0, the best SaaS businesses hold an LTV to CAC ratio above 3 and recover their CAC in 5 to 7 months, and a payback beyond 12 months leaves profitability anemic. Both figures need the ad spend of a period and the revenue of the customers that spend brought, which usually live in two tools nobody reconciles weekly.

Adrails reads them together. The agent has ad spend by campaign over any period, and from Stripe the active subscriptions, trials, MRR, ARR, collected payments and refunds, with customers by billing cadence; from RevenueCat the same for a subscription app. Ask what a paying customer from a campaign cost last quarter and what those customers pay each month: the answer states its sources and periods, and the arithmetic stops where the data does, with no forecast attached.

Each source stays in its own currency and is never merged into the platform's revenue. When Stripe and Meta disagree on what a campaign earned, you see both figures and decide which one your CAC payback uses.

SaaS PPC splits into two jobs. Google Ads for SaaS captures people already searching for the category or a competitor: Search campaigns on the terms your trials come from, with Performance Max and Demand Gen for reach. Facebook ads for SaaS create the demand search cannot capture yet: B2B advertising on Meta is a Leads or Sales campaign to a defined audience, with the free trial or the demo as the offer.

The Campaign Manager prepares both from one brief, as an editable hierarchy of campaign, ad sets and ads with the tracking parameters added to the ads. Everything is created paused. On Meta a split test can vary the audience, placements or bidding of an ad set, or the text and creative of an ad; on a Google responsive search ad it varies the headlines and descriptions. Google Ads opens once Google finishes verifying Adrails, so connect Meta for now.

Decide low-volume B2B PPC tests on the step that has volume. A verdict needs at least 10 conversions per variant and 95% confidence, so a test decided on trials or demos settles in days where one decided on paid plans may never settle.

• Google Ads Search for category and competitor intent, B2B Facebook ads for demand creation
• One variable per split test, decided on CPA or conversion rate
• Decide tests on trials or demos, then read the paid step in the Tracking tab

Adrails tracking has two parts. A script on your pages keeps a first-party visitor id for a year and the UTM parameters and click ids, fbclid and gclid among them, for 90 days, and records page views. Your server sends the sales and leads, signed with a server key that never goes in a page: only these signed events can reach Meta and Google Ads, because a forged sale would teach a platform's bidding to buy more of nothing.

For Meta, each signed event goes to the dataset you chose right after it is recorded, with its event_id so Meta counts it once with your pixel, and the customer's email hashed with SHA-256. For Google Ads, signed events carrying a gclid go in hourly batches once they are 6 hours old, to the conversion action you chose for Purchase, Lead, Sign-up, Subscription or Trial started; when you set Google up later, the signed conversions of the last 7 days are sent too.

Two limits protect the platforms from a leaked key or a broken integration: a largest value per event, 100,000 by default, and 5,000 events per day per platform. Events past them are still recorded in Adrails and held back from the platforms. Settings shows what was sent, what waits and what was refused over the last 30 days.

• Use your Stripe customer or invoice id as event_id so a sale is never counted twice
• Store gclid, fbc and fbp with the account at sign-up to send the paid conversion later
• Pick the Google Ads event that matches the step you want its bidding to learn from

An ad threshold automation watches a campaign, ad set or ad metric over today, the last 7 days or the last 30 days, checks it every hour and fires at most once a day for each item that crosses the line. The CPA alert template posts to Slack or Discord; Stop-loss and Spend without results pause what spends without a result, either at once after Adrails checks on the platform that nothing changed, or after waiting in Priorities on Home for 24 hours for an administrator to apply it.

Free trial ads need the same guardrail on cost per trial, since a trial that never activates costs the same as one that converts. A weekly review automation reads the accounts, asks an agent about the rows and emails the result with the top and worst ads. Every pause is logged with the figures that led to it, and a budget change an agent proposes is capped at 30% per change.

• Up to 5 threshold automations switched on at once, 25 automations per workspace
• Pause automatically, or hold each pause in Priorities for 24 hours
• Weekly review to Slack, Discord or email, with an agent's read of what changed