One of the sessions at SaaSCon that I enjoyed the most was Paul Johnston's "What Video Games can Teach us About Solving for User Adoption". It was a very funny presentation and he's great presenter (hey, his keynote session was the only thing between a large crowd and the event evening cocktail after a long day, and everybody stayed, and asked questions, and laughed!). His keynote prompted me to write this post which I have being postponing for a while.
In my experience, whenever I discuss SaaS application architecture or talk to people that are considering building a SaaS enabled application, they give for granted that the UI should be browser based. I sometimes get stares when I mention that their SaaS app might very well not have any UI at all, if all it does is provide a service for other applications to use.
Not everybody, but the vast majority I've talked to assume that to qualify as SaaS their applications should have a browser UI by default. (Maybe I talk with a not big enough representative sample). The fact that most demos, presentations and samples from bigger players in the SaaS market are using mainly this UI technology with various levels of sophistication might have an influence in this perception.
An application should choose the best channel and method of interaction, based on the experiences they want to provide: could be pure HTML based browser, AJAX enabled, a mobile device, a desktop smart client, etc. It could be a portfolio of these UI technologies. It really depends on the scenario they want to support support, but all of them qualify as being "SaaS".
The fact that many have decided to invest on AJAX extensions to their web based UIs exposes an underlying interest in enhancing the interactions between users and the apps, using it mainly for increasing responsiveness by decreasing latency, reducing roundtrips, etc. however, as with any other tool, you can fill your app with AJAX juice and still have a terrible experience.
Anyway, technology apart I think Paul's presentation highlighted the importance of overall User Experience in applications delivered as a Service, especially those designed to target the "long tail" market (like SMB, Home Office, etc.). These users are probably closer to the consumer market in terms of technology exposure. Somebody with little experience using "Line Of Business" solutions will highly appreciate an intuitive, simple to understand, visually rich application as opposed to a feature rich app that requires too much training to understand and use.
A great UX makes users want to use your system, as opposed to having to use it.
Paul's company, Entellium, seems to have invested heavily in usability and it shows on the demos I saw in their booth.
The front end for their SaaS CRM is a WPF based smart client, but besides "UI sugar", I saw an intuitive, visually appealing UI that goes beyond the "navy gray", squared, grid and treeview intensive UI. At the same time, being a smart client, they have enabled scenarios that would be impossible or difficult to do with a pure browser approach, like offline operations.