Plex Systems is a SaaS manufacturing ERP provider based in Auburn Hills, Michigan. They have grown substantially and currently have over 250 employees. For a long time they have been doing some very unique things with their community and they are leaders in community driven product enhancment. In fact any customer can pay for an enhancement, which becomes part of the service which any customer can then use. You can read more in their whitepaper on the topic.
Open Source projects rely entirely on their communities for most everything and I think that there is a lot we can learn from Open Source projects which is applicable to SaaS communities. The community manager at Ubuntu has shared how they incorporated gamification into their community and it is a great case study on that topic.
Cloud Resources `for Developers
A recent Forrester report indicated that Amazon Web Services (AWS) is the most popular cloud development platform for developers by a wide margin. This is especially interesting since AWS is not truly a Platform as a Service (PaaS) and does not have some of the features that a PaaS would have. The main reason for it's popularity is that developers believe it is the quickest way to get their work completed.
I believe that it is also because of the pace of innovation at AWS. As an example since January 1st, AWS has announced 8 new features in a timeframe when many other cloud providers have not announced any. If you have the perception that AWS is not suitable for enterprise level applications I suggest you take a look at their current offers.
Azure is the second most popular cloud platform for developers and you can read about some of the reasons why here. Google, Force.com, and Rackspace are also popular and only slightly behind Azure.
Protecting the data that you have in your SaaS application and complying with all of the laws which might apply can be a substantial undertaking. For personal identifiable information (PII) there are now laws in 46 states which apply. These are primarily focused on breach notification. A resource that I highly recommend on data privacy when dealing with PII is a McAfee resource
which gives a summary of the laws in each state and in international locations. Of course this is not a substitute for legal advice but it can be very useful if you want to understand what laws apply in certain circumstances.
There are new HIPAA laws which just were announced in January. Some of the changes apply to service providers such as SaaS companies. The biggest change is that there is now more responsibility put on service providers to comply directly with the law. You can read a brief summary here
and I suggest that if your application might be used for data that you think may be protected personal health information that you do more investigation on the topic.