If history is any indication, however, SAP may indeed do so if the discontent is sustained and strong enough. In 2008, it made concessions regarding an unpopular support price hike following a protracted outcry from user groups.
Market pressures could also force SAP's hand with Fiori as it tries to compete with newer rivals such as Workday, which recently rolled out a next-generation, HTML5-based user interface for its cloud-based human resources and financial software, at no additional cost to customers.
"In a cloud world, you'd expect Fiori to be part of the upgrade cycle," said analyst Ray Wang, chairman and founder of Constellation Research. "Many of our customers feel that paying for Fiori hurts the overall SAP relationship."
(Computerworld UK editor Mike Simons contributed to this report.)
Chris Kanaracus covers enterprise software and general technology breaking news for The IDG News Service. Chris' email address is Chris_Kanaracus@idg.com