Summary: For my blog, RSS is a much more important content format than HTML these days. In one of my posts, five and a half times more important!
Darren Rowse writes that Page Views per user for blogs is on average relatively low - less than 2 pages per visit. After a bit of research Darren came up with the figure of 1.7 Page Views per visitor for the average blog. I looked at my own stats and found that my Page Views per Unique Visitor was a lowly 1.4 (yikes!) last month. As Darren noted, the average blog reader looks at less than two pages per visit. If you look at our old friend Alexa, you'll see that most of the top websites in the world have high Page Views/Visitor numbers - i.e. they're "sticky" to use an old 1.0 term. The world's most popular website, Yahoo!, has a whopping 16.6 Page Views per user.
I've done a lot of research using Alexa over the past 6 months or so and I know that most good web sites average around 4-5 Page Views per user. So blogs are definitely below average, compared to more traditional websites. That's to be expected really, because RSS has become the method of both delivery and reading blog content. Especially so for a blog like mine, which offers a full-content RSS feed and is mostly read within RSS Aggregators. That doesn't worry me (quite the contrary), although it does mean I earn less revenue from ads on my site.
I was discussing RSS page views with someone last week, so I decided to compare the RSS and HTML page views from a single post of mine - Portals 2.0 flesh out their product lines. According to Feedburner Pro, that item was viewed 4884 times in my RSS feed over the past 30 days. Looking at the same post in MeasureMap (which btw is almost unusable currently due to extremely slow downloads!) it's been viewed 876 times on my website over the past 30 days. So with that rough calculation, my posts are viewed 5.5 times more via RSS than on the website! I'll do more analysis when I get time, but even this small example proves that RSS is a much more important content format than HTML these days, for my blog. I'd be interested in knowing if this is the case for other blogs.