There are still too many users asking this question, so I will attempt to give the short and long version of the answer here..
Short Version Answer: The database containing the data which populated page UsageDetails.aspx is gone. You could use the new Popularity Trend feature, found in the Site Settings page.
Long Version Answer: The page UsageDetails.aspx was never even available through the User Interface (UI), one had to know about its existence to type its URL in the address-bar but that is kind of a hack, never really supported..
Here is the official statement from the product group:
Why has it changed in SP 2013:
Configuration is quite upfront, here is an example of Bing Webmaster Tools configuration instructions:
" Bing Webmaster Tools helps you track important metrics (like impressions and clicks), provides insights about how Bing is crawling and indexing your site, and gives you more control over how Bing interacts with your site. You have three options for verifying your site:
1. Place an XML file on your web server 2. Copy and paste a tag in your default webpage 3. Add a specific CNAME record to your DNS"
Have a nice and productive day,