The Coyote Blog posted a summary of what it takes to host a Blog Carnival and some experiences re: increased blog traffic associated with hosting etc. here:
I like his metaphor for carnivals: "rural electrification for the Blogosphere".
His suggestions to hosts are right on so go and read his post: start your Word file a week in advance and work on building it one link at a time as the entries come in. He hosted the Carnival of the Vanities, which is the original carnival with a large readership, so a big increase in hits is not surprising. Likewise for the Carnival of Capitalists, also an old and established carnival. It is interesting to see his sitemeter stats. Apart for obvious weekend dips, he saw huge spikes the day after posting the carnival that subsided back to his normal daily average after just a couple of days.
My experience is somewhat different. I have hosted four carnivals so far. The Carnival of Balkans I just posted, while the Eastern Europe is still asleep. I will see how the traffic goes tomorrow.
The Tangled Bank is quite a well-known and established carnival. I got a nice peak when I posted it, but the elevated traffic persisted for a very long time. I still get hits for it two months later.
The Carnival of Godless was a huge success. I got at least 300 extra hits the first day, and almost as many over the next several days, and I still get quite a lot of hits for it a whole month later.
The Tar Heel Tavern was tricky. I hosted the very first edititon. This carnival has the narrowest potential audience. Its audience, with a couple of exceptions, has never heard of carnivals before and are still quite uncertain what that all is. Only a couple of blogs did the customary "duty" of linking to it and advertising it, even if they themselves had posts on it. I guess they are still new to the phenomenon and do not yet know all the ropes. And still, I saw a nice rise in traffic when I posted it, and I am still seeing hits to it today.
I guess the main difference between my experience and Coyote Blog's (and another one's: http://www.theglitteringeye.com/archives/000809.html) is that every carnival I hosted permanently raised my daily average. It may something to do with the nature of the actual carnivals we hosted: his were general-interest carnivals and his blog was probably already known to most of the readers from his old submissions to those carnivals. I hosted more narrow-interest carnivals for which my hosting attracted people who were glad to find another blog of the same interest. They looked around, bookmarked and blogrolled me and kept coming back. It is a difference between carnivals that serve mainly as weekly magazines (once you read an issue your throw it away and wait for the next one) and carnivals that serve mainly as town-squares or meeting places that serve as centers for building communities.
My "feel" so far is that having a post on a carnival brings a few dozen hits and up to about ten new "friends", i.e., regulars who keep coming back. The hosting, on the other hand, brings a total of about a couple of thousand hits over a number of days and results in about a hundred new blogrolls and about a couple of dozen new regular readers.
I am interested to know about other people's experiences.
Update: Blogger was very misbehaving last night and this post published four times. In deleting three extra copies I inadvertently deleted a comment by Orac. But I have it saved and will reproduce it here:
When I hosted the Skeptics' Circle two weeks ago, I got over 1,000 hits the first day, and it took several days before my daily average fell back to "normal." In fact, although it's too early to say, I think it permanently raised my daily hit count. Yesterday was the first day my hit count was back where it was before I hosted the Circle.Given that I will be hosting Grand Rounds on March 15 and Tangled Bank on April 6, I expect similar, perhaps even bigger spikes. Hopefully, it will permanently increase my readership.
Yes, I got a lot of hits when I had my posts on Skeptic's Circle and Grand Rounds. I am hosting the Circle the end of March and Tangled Bank (on Circadiana) in late April. I will see what happens.