Why buying agent suites is both the ROI winner and the quiet threat to per‑seat SaaS

Buying agent suites wins ROI — and it’s quietly eroding per-seat SaaS revenue

Most companies frame build vs buy as an engineering trade-off. That misses a sharper business fact: when buyers choose packaged agent suites they not only get to production faster — they also convert seat-based spend into usage/outcome fees, shrinking the unit economics that fueled legacy SaaS ARR.

This article explains why, with numbers and a simple CFO shortcut to estimate seat-risk.

The common belief and why it feels right

The usual take is: build if you need control and buy if you want speed. Analysts backed both sides with big headlines: MIT Project NANDA reported 95% of GenAI pilots produce no material return, while BCG highlights a 5% club capturing most gains. Those findings push leaders to question whether to invest in internal platforms or buy vendor agents.