I've described several times in the past that service providers (typically ISVs) and service consumers (typically Enterprises) should look at SaaS with quite different lenses.
Lately, I have been summarizing these different perspectives as follows:
- service providers care about efficiently doing 1-to-many delivery
- service consumers care about many-to-1 consumption
Below a simple image illustrating this concept.
No rocket science of course, but useful to describe that enterprises do not care about the same things that ISVs do. My preferred example (as I mentioned here) is multi-tenancy.
Multi-tenancy is a 1-many delivery concern and therefore ISVs should care about it. Enterprises on the other hand, should be much more interested in the integration / composition features of the service provider such as single sign on support, import/export interfaces, events generated, remote management features etc. as they impact the many-to-1 consumption.
As an enterprise I would not spend too much time on how/whether my providers implemented multi-tenancy, but rather make sure that the SLA includes clear clauses around data protection and heavy penalties for data mismanagement (e.g. data leakage, data corruption). If I want or need to be more conservative with my data policies as an additional layer of protection I would consider doing (local or through another service provider?) backups of critical data. Reinforcing my point of caring more about integration points.