And you probably guessed it wrong, Wikia won't be serving any advertising on your pages - on the other hand, you can type in your Adsense Publisher code while signing up and the entire advertising revenue will flow into your account.
Wikipedia founder Jimmy Wales and Wikia executive Gil Penchina are saying that they haven't thought of any business-model out of Openserving yet. They just want the hosted website to link back to Wikia.com. Pretty reasonable [think Google juice]
So why is Wikia giving away all this for free when it will cost them money for buying all those additional servers, hard disks, power bills, etc ? The one word answer is Youtube.com.
There's a simple connection between Youtube and Wikia's Openserving.com - When Youtube launched, they asked users to upload and share their home video clips with other users via Youtube for free.
The company itself wasn't making any money from these grainy clips but over time, Youtube successfully managed to build a community of millions of users and it reached a point when the entire web became addicted to the "user generated content" stored on Youtube.
That's when Google stepped in with a check of $1.65 billion. It may not require any rocket science to envisage a similar future for Openserving.com.
We are not living in the 1999 era of freebies anymore. But yes, this announcement will not be music to the ears of other hosted wiki platforms or wiki farms that offer ad supported wikis.