ERP. Forget about being fully SaaS but be SaaS enough so that what you build to scale in the cloud can also scale out of the cloud. Edit: what I mean is that mo

ERP. Forget about being fully SaaS but be SaaS enough so that what you build to scale in the cloud can also scale out of the cloud. Edit: what I mean is that most companies interested in SaaS are actually more confident to host their own little version of your solution for their needs. Spend time studying OpenERP because it's succesful and you'll have to compete against it. Their platform is a great case study: it's powerful and modular while being difficult to take over. Their code base is a mess and yet they have developer's traction. There's a huge market, no matter what you plan (a platform or a solution). If you go for a platform, avoid small projects.