At last, Google is revealing its split on AdSense: 68% to publishers for content ads, 51% for search ads.

I had two primary complaints about Google in my otherwise admittedly and obviously wet-kiss book, What Would Google Do?: Google’s policy aiding government censorship in China and its opacity on advertising relationships. The first is pretty much fixed and this morning, Google is addressing teh second. so is the second. (Uh-oh, now I have fewer excuses not to be a fanboy.)

At a press meeting with Google execs in Davos in January, I pressed them about the advertising openness, having discussed the issue with publishers at DLD in Munich right before. In Davos, Google’s president of global sales, Nikesh Arora, replied that the company was reconsidering its transparency on AdSense. This morning, they’re revealing the deal in a blog post (to which I’ll link as soon as it’s up; this news was embargoed for 10a ET). From the post:

Today, in the spirit of greater transparency with AdSense publishers, we’re sharing the revenue shares for our two main AdSense products — AdSense for content and AdSense for search. . . . AdSense for content publishers, who make up the vast majority of our AdSense publishers, earn a 68% revenue share worldwide. This means we pay 68% of the revenue that we collect from advertisers for AdSense for content ads that appear on your sites. The remaining portion that we keep reflects Google’s costs for our continued investment in AdSense — including the development of new technologies, products and features that help maximize the earnings you generate from these ads. It also reflects the costs we incur in building products and features that enable our AdWords advertisers to serve ads on our AdSense partner sites. Since launching AdSense for content in 2003, this revenue share has never changed. We pay our AdSense for search partners a 51% revenue share, worldwide, for the search ads that appear through their implementations. As with AdSense for content, the proportion of revenue that we keep reflects our costs, including the significant expense, research and development involved in building and enhancing our core search and AdWords technologies. The AdSense for search revenue share has remained the same since 2005, when we increased it. We also offer additional AdSense products including AdSense for mobile applications, AdSense for feeds, and AdSense for games. We aren’t disclosing the revenue shares for these products at this time because they’re quickly evolving, and we’re still learning about the costs associated with supporting them. Revenue shares for these products can vary from product to product since our costs in building and maintaining these products can vary significantly. Additionally, the revenue shares for AdSense for content and AdSense for search also can vary for major online publishers with whom we negotiate individual contracts. Of course, we can’t guarantee that the revenue share will never change (our costs may change significantly, for example), but we don’t have any current plans to do so for any AdSense product. Over the next few months we’ll begin showing the revenue shares for AdSense for content and AdSense for search right in the AdSense interface.

They’re also not revealing splits for YouTube, a program that just started. Note also that big publishers, such as the New York Times Company, have long known — and negotiated — their splits, which also aren’t revealed. A Google spokesman told me last night that these splits hold for classic AdSense pay-per-click ads and also for newer display, CPM ads. They also hold globally.

How do the splits compare? It’s not uncommon for ad networks to take 50% or more. BlogAds, one of the more generous networks, customarily takes 30% on sales it makes and has other models (if sales come through a publisher site, only 14%; they also offer networked sales).