Q:

SQL Azure Federations pricing

If I have a single 1gb database it costs $10 per month. If I set up federations, so for example I have 5 federations, is it still $10 per month or does each federation cost $10 ($50 total) ? 
If it is the former that is better as I can just have a single federation per tenant (client) and increase the database size as more clients sign up.

A:

With Federations, you can scale your application out across multiple federation members. Each federation member is a SQL Azure database and can be controlled as you can do with your databases today in terms of max size and SKU (web/business). You can choose to scale out to lots of small 1 GB databases, or fewer 10 GB databases for example.
In SQL Azure, you get billed on the collection of all databases you use in the system prorated to a day. In the case of federations, the same logic apply; the cost of the federation is the collection of its federation members (+ the root database which can be any normal database).

