Free is great for demos and proofs of concept, but that doesn't mean you want to put free items into production systems. If the cloud freebie is from a consortium, government agency, open source vendor, or university with solid funding, you're probably not running a big risk. But if the freebie is coming from a small startup, there's no way of telling (let alone assuring) how long it will be around in its current form. So if you leverage these Cloud freebies, make the integration as light-weight and modular as possible, and put a budgetary place-holder in the out-years in case you need to replace the application or service with something else or your own code.

If the service or app you're looking at using is available commercially, the lowest long-run costs will come from paying for that version. Most of the fees are nominal in comparison with the DIY (or should I say re-DIY) project that can result from depending on freeware versions.

If paid-for cloud services can have seriously lame support (and the answer is "yes"), it's irrational to expect better support from a freebie. I'm not going to mention names, but you're definitely going to want to research your cloud vendor's reputation for support before you commit in a big way. Go to their discussion groups, user forums, and other online sources to find out what their service levels really are. If your Cloud vendor also has on- premises versions of their software, make sure to separate the reputation for their high-cost enterprise support from the one that's relevant to you in cloud-space. You'll find that some old-line vendors that really ought to know better are way under-investing in support...which means you'll have to invest more in self-support.

The cloud doesn't change this part of software economics.