With SAAS, if the software is barely usable but lacks competition, vendor gets paid even if they don't fix bugs or broken functionality. When paying up-front, t

With SAAS, if the software is barely usable but lacks competition, vendor gets paid even if they don't fix bugs or broken functionality. When paying up-front, there always is competition - your own old version; so the vendor has strong financial motivation to make improvements since the recurring "maintenance" upgrade revenue is conditional on them, unlike in SAAS.