Single sign-on is essential to driving engagement and usage of SaaS applications in large and mid-sized customer organizations. SAML is often promoted as an industry standard in the area, but is it really the de facto standard a SaaS vendor needs to drive growth?
No.
SAML is a protocol, a language. Languages are great for communicating, but a certain language is only useful when communicating with other speakers of the same language.
In business, the value of a language is dependent on how big a share of your current and potential customers speak it. Your choice of language(s) can greatly affect what kind of business you can expect: doing business only in Finnish limits your market to 5 Million people, whereas English lets you address more than a Billion people. You have three options.