I recently read a piece in one of the IT trade publications about why buying infrastructure via a cloud provider (Amazon in particular) was a bad deal, and how one would be much better off buying storage in-house. As is often the case, the opinion-piece compares apples to oranges, and the analysis is so flawed, one can't really make any use of the conclusion. However, my experience is that the piece is hardly unique in its flaws, and that motivated today's post.
The usual analysis is to compare the cost of storage when purchased as a consumer-grade disk drive v. storage when purchased via a cloud-based infrastructure provider. The numbers -- $100 for a 2TB drive from Best Buy v. $100/mo for 1TB of S3 space at Amazon -- are thrown out as directly comparable, and thus it is plain to see that it is better to spend that $100 just once to get storage rather than spending the same amount of money each month (and for less storage to boot).
The analysis then usually performs some hand-waving about how disk drives sometimes fail (really?) and how they don't last forever (shocking!), but these facts are just in the noise, and it really is clear how much better one is purchasing storage rather than "renting" it in the cloud.
However, this sort of comparison is like looking at the cost of one's grocery bill for a given meal v. the cost of having a meal at a restaurant. The first is merely one part of the second, and they simply are not the same thing.
A disk drive from Best Buy can be a very useful thing. I myself own one of these very same drives, and I use it every couple of weeks to back-up a PC we have at home. (Clearly my disaster recovery process is not good.) Because the storage only needs to be "lit" every so often, and only needs to be accessed from a single location, it works well.
If instead I needed my storage to be available 24 x 7, and to have some credible DR plan, this wouldn't do. Or if I wanted to be able to use a lot more storage some days (or weeks or months) and less storage on others, then buying storage for peak isn't so good. Also, when it is "lit" my storage consumes some electricity to operate. So maybe an analysis that includes things like mirrored copies, electricity, front-end access systems, the network, and ..... gets to a more apples-to-apples comparison.
The cloud may be the best solution to some problems, and a dreadful solution to other problems. Maybe way overpriced. But a lot of different stuff makes up "cloud storage" and the underlying media is only one of many; in fact, it may be the least expensive component.