Alphabet’s stock fell about 13% on Thursday after third-quarter results paired slower Search revenue growth with massive AI infrastructure spending. The market reaction has reopened a sharper question for performance marketers: who is actually paying for Google’s AI transition?
The numbers behind the slide
Alphabet shelled out $51.36 billion in capital expenditure during Q3 and posted negative free cash flow of $9.07 billion. At the same time, Search usage is growing, but that growth is not translating into equally strong revenue growth.
For advertisers, the concern is straightforward. Google can close its revenue gap by creating more ad slots, charging more for existing traffic, or both. More placements could reach new customers — or push budgets toward exploratory AI conversations that do not convert quickly. Higher CPCs only work if conversion rates or customer value rise in step.
Why marketers feel like the bill is landing on them
Some performance marketers read Q3 as evidence that Google is protecting revenue at advertisers’ expense. Max Anderson pointed to unwanted clicks, broader keyword matching, auction pricing pressure, and campaigns spending up to twice their daily budgets. Daniel Koss compared it to traditional media owners raising prices as demand declines.
Worth noting: many of those behaviors sit inside Google’s published rules. Daily budgets are averages, and campaigns can legally spend up to twice the daily amount. High CPCs can also result from Ad Rank thresholds even when no competing ad sits directly below yours. None of that proves Google changed its auction to fund AI — but it also doesn’t comfort a brand paying for irrelevant clicks.
What Google still has to prove
Google has said click-through rates for sponsored and organic product listings in AI Mode look similar. That tells advertisers people will click ads inside AI experiences. It does not tell them whether those visitors convert, how lead quality compares, or how long the purchase window really is.
The reporting gap makes this harder. Google currently merges AI Mode performance into standard campaign and search term reports, so advertisers cannot cleanly compare acquisition costs, conversion rates, or lead quality between AI Mode and traditional Search. That means brands are being asked to fund placements they cannot yet analyze separately.
What to do before you scale AI Search spend
- Audit search terms weekly for irrelevant clicks and rising CPCs.
- Set daily budget caps conservatively if a campaign is routinely spending near 2x its average.
- Ask your Google rep for separate AI Mode acquisition, conversion, and lead-quality reporting.
- Treat AI Mode as a controlled experiment until the data proves customer value.
The Q3 selloff doesn’t prove Google is making advertisers fund AI, but it makes the burden of proof clear. Google needs to show that AI placements deliver customers, not just clicks. Until then, advertisers should track the incremental value themselves.
Source: Search Engine Journal
