Along with other announcements at MIX07 today, we've rolled out clearer and more consistent terms of use for Windows Live Web Services. Here's an overview:

Microsoft is enabling access to a broad set of Windows Live Platform services with a single, easy-to-understand pricing model based on the number of unique users (UUs) accessing your site or Web application. These terms are intended to remove costs associated with many Web applications and provide predictable costs for larger Web applications. There are some exceptions to the UU-based model: (1) Search: free up to 750,000 search queries/month, (2) Virtual Earth: free up to 3 million map tiles/month; and (3) Silverlight^tm Streaming: free up to 4GB storage and unlimited outbound streaming, and no limit on the number of users that can view those streams. Beyond these limits websites and users will be required to conclude commercial arrangements for these services with Microsoft.

The services included in this TOU are: Contacts, Photos, and Silverlight Streaming, Search, Virtual Earth, and Windows Live ID.

The pricing structure for the services announced at MIX07 is as follows:

• Services exposed through controls have no user limits or fees.
• Sites or Web applications with fewer than one million UUs pay no fees. See above for limits on search, Virtual Earth, and the free Silverlight Streaming service.
• Once the service emerges from beta, sites or Web applications with more than one million UUs will be charged USD $0.25 per UU per year for the covered services or will engage in ad revenue sharing with MSFT. Given that the service is currently in beta, we will not be charging websites today nor do we anticipate large commercial sites building on these services in the near term.
• For Search and Virtual Earth, sites using more than the limits on free services noted above will need to conclude commercial agreements with Microsoft outside of the $0.25 per UU/year noted above.
• The one million UU threshold will be measured as a quarterly average, to smooth out usage spikes that sites may experience