MarTech replacement rises, but marketing stacks keep getting bigger

MarTech’s latest stack surveys showed a blunt contradiction for agencies: software replacements were slowing, yet the stack kept getting bigger. In the 2025 Replacement Survey, 59.9% of respondents said they replaced a marketing technology application in the previous year, down from 69.8% at the 2022 peak. But among the organizations that did replace something, 62.9% added applications to their stack and only 22.6% saw the stack shrink. For SEO retainers, that meant a swap often did not simplify anything, it just added another system to reconcile, another dashboard to defend and another place for client data to drift.

That is the integration tax in plain English. MarTech’s 2025 State of Your Stack Survey found that 62.1% of respondents used more tools than they had two years earlier, even as data integration remained the biggest stack-management challenge, cited by 65.7% of respondents. Budget constraints and vendor management were still pressuring operations, but organizations kept layering point solutions around core systems instead of cleaning up the architecture. Scott Brinker said the expansion was surprising under fiscal discipline and suggested AI may have been driving much of it. Nearly one-quarter of the tools and capabilities marketers planned to add were homegrown solutions, a sharp reversal from the prior year’s near-extinction narrative. In the replacement survey, by contrast, 96% of the swaps were commercial applications.

The churn was not spread evenly. Marketing automation replacements fell from 31.1% in 2024 to 19.4% in 2025. CRM replacements dropped from 22.1% to 9.7%, and email platforms declined from 24.3% to 13.7%. SEO tools, meanwhile, became the most-replaced category in 2025, with more than 20% of respondents who replaced a tool saying they replaced SEO software. MarTech also said analytics and BI was the only growth category, which tells you where the pressure is moving: agencies are not just buying more search software, they are trying to bolt new measurement onto an already crowded reporting stack.

For agencies, that is where margin gets quietly eaten. Every extra application adds one more sync to break, one more field map to maintain and one more attribution argument to settle before the work can even start. The shops that win will be the ones that consolidate the core systems, keep the SEO, analytics, CRM and email layers tightly integrated, and treat stack governance as an operating discipline instead of a cleanup task.