At a guess - corpos like Big 4 consulting agencies and some extreme fintech ones, also corpos like Oracle and the like. And at another guess, outside of a legal agreement with a fixed time period, probably nothing hold them from quickly switching to a better model provider, if any comes ahead.

I'd say more likely the FAANG type companies, suspect big 4 are much smaller.

But the FAANG customers are the opposite of sticky, given that they all have their own models.