Looking out at yesterday’s Amazon S3 (Simple Storage Service) outage through his Microsoft Watch-colored glasses, my colleague Joe Wilcox views the hosted storage slip-up as a selling point for Microsoft’s Software-plus-Services twist on cloud computing.

The Software-plus-Services pitch goes something like this: Rather than jump into cloud-based services with both feet, organizations and individuals should pursue a blended strategy, based on traditional on-premises software, complemented by hosted services where appropriate.

The Software-plus-Services strategy makes a lot of sense, and organizations investigating whether to shift vital systems from an on premises to a hosted model shouldn’t allow themselves to get so caught up in cloud excitement that they overlook the relative immaturity of hosted services.

With all that said, however, it’s important to keep in mind that the tag line “Software-plus- Services” doesn’t tell the whole story. Sitting behind that familiar and friendly word, “software,” are a chain of significantly more sticky concerns. A more accurately descriptive slogan might be, “Software-plus-Hardware-plus-Power-plus-Bandwidth-plus-Real-Estate-plus-Management plus-Services.”

When you take into account everything that’s required for a business to host its own software—particularly for a startup out to break into a market, or an established player looking to avoid being bumped out of its place—putting up with a certain amount of downtime can be viewed as a cost of staying in business.