Yes, they have Atom and Blogger, but Google doesn’t yet have what many feel is a glaring omission: RSS. Now, according to one of the former Blogger.com brainchilds, Evan Williams, Gmail has something called Web Clips coming which will allow reading RSS feeds through Gmail. And it has ads too.

Richard MacManus from Read/Write Web writes:

If I was to guess, I’d say they want to harness RSS. Most of their huge take of advertising revenue comes to them via webpages - their own pages, plus external webpages that use Google Adsense. So Google wants to ensure that revenue doesn’t get siphoned off if they make content available via RSS.

The one thing Google has to be extremely careful about is inviting more click fraud. This, I think, is what they’ve been spending a lot of time experimenting with before jumping on the RSS train. Once they sort these technical details out, I think that we’ll see Google help popularize an exciting advertising channel that is still in its infancy: RSS advertising.

Some will call this the beginning of the end when many sites start running Adsense in RSS — and if Google makes this available as an option, this will increase the noise to signal ratio. However, unlike email spam which is a hassle to opt-out in most cases and often unsolicited (harvested emails or otherwise), RSS subscriptions are opt-in and easy to opt-out.

I hope at the same time more support for HTTP authentication in RSS aggregators is also popularized so that publishers can offer readers the ability to receive the content ad free in exchange for a small subscription fee. Some aggregators do offer password protected feeds today, but it’s not a well used or very popular function … yet.

• Google Adsense RSS beta public launch
• Adsense rumoured smart pricing
• Google makes it easier to add Adsense to Blogger
• Gmail adds 30-day auto spam removal … I think
• Gmail spam filter sucks too, 3 GB of spam in less than 6 months
• RSS for Adsense readers aren’t clicking in large numbers