Things are pretty easy: The BOS server gathers the information for the services, and these informations are then available from a single point - you choose which services to use and how. It couldn't be more simple.

The services are provided free of charge, and you don't need to ask permission to use them, which some have thought due to the copyright notice. I would like to know, though, if and how you are using them, only as a means to make sure the services are actually used, and that they do what they were intended to do. So if you are using them on your web site, please visit the Links page and add your site accordingly (this is optional, but recommended).