I’ve been talking recently to quite a few companies who decided to take the plunge and move their services into the cloud. Some were just starting while others had plenty of mileage under their belts. A major question posed to these companies was, why did you switch to the cloud?

Here’s what I found.

1. Economy

The most frequent reason cited was that the cloud wins in cost. This isn’t fantasy, it’s reality: these companies significantly slashed their costs by switching. One CTO proudly mentioned his board of directors’ enthusiasm upon seeing the the new bottom lines.  Overall, there was agreement that despite the initial price tag – some work required to switch – it’s totally worth it.

2. Elasticity

Scale up, scale down, on-demand, the sky’s the (theoretical) limit, ’nuff said.

3. Development and testing

The process of developing, debugging and testing is not fully addressed in a classic deployment environment. It gets easier by an order of magnitude in the cloud. Staging environments, parallel testing and ad hoc farms can be created and destroyed at the developers’ pleasure.

Although this usually wasn’t the primary motive for switching to the cloud (as opposed to the reasons above) it was a bonus many chose to highlight.

4. Experimentation

The cost of experimentation is very low in the cloud. This is making it easy for companies to test drive new concepts without making a large up-front commitment. If it sticks, the transition into a fully-fledged application is smooth.

Non-reason:  Proprietary technologies

Notable absentees in the motivation to switch to the cloud were the new but proprietary services offered by several providers. There appears to be a notable degree of resistance to vendor lock-in, which is the Achilles’ heal of services such as AppEngine, SimpleDB and SQS alike. This is perhaps the secret to Amazon’s success in the cloud – its strongly decoupled offering allows for a pick-and-choose approach, without major paradigm shifts – evolution not revolution. Companies clearly prefer standard tools based on tried and tested technologies.