The four content delivery networks that teamed up with Google Inc. earlier this year to provide low-cost traffic optimization for its public cloud probably won’t be too happy to hear about the new homegrown caching service that the search giant started rolling out this week. Much like Windows tablet manufacturers after the launch of Microsoft Corp.’s Surface, they’re now confronted with a noticeably reduced business opportunity, although the situation is not quite the same.

Redmond, which happens to be one of Google’s biggest rivals in the infrastructure-as-a-service market, similarly offers a native content delivery service for its platform, while Amazon Inc. has likewise taken traffic optimization into its own hands. Moreover, both offer users the ability to use third party alternatives, with Microsoft even going as far as partnering with Akamai Technologies Inc. a few months ago to provide native support for its competing network. The alliance reflects a focus on providing users with freedom of choice that trumps functional overlaps for all three providers.

In that respect, Google, which didn’t mention the launch of Cloud CDN on the official blog where new additions to its platform are announced, is merely trying to catch up with the competition. Like its rivals, the search giant is taking advantage of its existing data center network to set up caching servers at key regions where customers can store their data and thus reduce latency for local end-users. The arrangement also makes it possible to keep services available during outages and and, perhaps most importantly for enterprises, provide protection against large distributed-denial-of-service attacks.

Image via jeferrb