I don't know how Amazon comes up with names for its products, but recently they all strike me as weird and stupid names. Do they confer with marketing first? Zocalo, Cognito? Really? These are the kinds of names you invent when you're looking for a cheap domain name for your startup. For Amazon, they don't make a lot of sense. They just seem like some executive out of their marketing depth and out of touch trying to…
"Parse"? OK, sure...but that's not any more functionally descriptive than "Cognito"...and Parse is a more narrowly focused company with a primary service...In the case of "Cognito" and "Zocalo"..., Amazon has to come up with names that are distinctive because they provide so many core services...so many that even me, an engineer, get them confused. Imagine the difficulty of a fly-by marketing person trying to differentiate between similar sounding names.
Furthermore, these names are distinctive industry wide...presumably, if Zocalo becomes big, you will no longer have to say "AWS Zocalo", but just, "Zocalo"...just like you do with "S3" and "EC2".
To drive home the situation that Amazon is in, let's consider another great product name: Dropbox. Unlike Parse, it is very easy to relate to the core service. But consider the phrase, "Amazon Dropbox"..."Dropbox" is unique compared to the currently named AWS services...but it has a huge collision with Amazon's core service, which is, stocking and shipping products. If Dropbox.com didn't exist, and Amazon used it instead of "Zocalo"...there is a considerable risk that people associate "dropbox" with some kind of packaging thing.