Google just bought FeedBurner for 100 million dollars. This is a 10x return on investment for the venture firms that funded that startup. I use FeedBurner for my RSS feeds on this site.
FeedBurner lets web masters setup RSS feeds for their sites that are compatible with a maximum number of RSS reading clients. It also tracks usage statistics, viewership, and where your RSS feed is being displayed.
The synergy with Google is clear: FeedBurner already duplicates a lot of work done by Google Analytics. For example, this site uses both Google Analytics to track usage stats as well as FeedBurner. A unified script will be a godsend. Also, it is commonly known that Google Personalize Homepage is one of the top RSS readers, according to FeedBurner. In other words, Google was sending a ton of traffic to FeedBurner, but wasn’t capitalizing on it.
FeedBurner supports embedded RSS ads. This is a crucial piece for Google Adsense for Content since RSS feeds often skip ad impressions from remote audiences that don’t actually visit your site but read your content in RSS readers. This was a market that Google had no foothold in, and FeedBurner basically owned it. Now, Google owns this potentially lucrative emerging market (FeedBurner is pretty much the only real player in this market segment).