Microsoft Ads is 60% cheaper and almost nobody is bidding — 90 days of data

Same offer, same landers, same keyword set, 90 days, Google and Microsoft side by side. B2B software, $89/mo product.

Google
Spend $22,400 · clicks 7,180 · CPC $3.12 · trials 412 · CPA $54.37 · paid conversions 94 · CAC $238

Microsoft
Spend $8,900 · clicks 7,020 · CPC $1.27 · trials 388 · CPA $22.94 · paid conversions 71 · CAC $125

So why is everyone still on Google
Because that is all of it. Microsoft gave me 7,020 clicks and that was the entire available inventory at those keywords — I could not spend more if I wanted to. Google would have taken another $60k.

The caveats

• Trial-to-paid was worse on Microsoft, 18.3% vs 22.8%. Cheaper traffic, slightly worse fit
• Audience skews older and more enterprise, which happened to suit this offer and will not suit a consumer product
• Reporting is thinner and the editor is worse. Budget an extra hour a week

Verdict: not an alternative to Google, but a 40% CAC reduction on the share of volume it can serve. Nobody should be leaving that on the table and most people are.

The inventory ceiling is why it stays a secret. Every agency that tries it finds a great CAC and then discovers it does not scale, so it never becomes the headline channel and never gets talked about.

This is the clearest version of that point I have read. Cheap and capped is a very different product from cheap.

Ran this test on a consumer ecom offer and got the opposite result — CPC lower, conversion rate far worse, CAC about the same. The audience skew does the work.

That is a useful counterweight and matches the caveat. Older enterprise audience suits B2B software and does not suit a $29 consumer product.

Worth adding: the import-from-Google feature makes the setup cost about an hour. The barrier here is attention, not work.

What does this look like after an update? That is where most of these fall over.