The Web-Tracking Tipping Point

The future of web tracking is simple to understand, but painful to acknowledge; we can’t rely on third-party cookies and JavaScript snippets anymore. The burden shifts from the user’s browser back to our own web servers, and this shift will add complexity to web stacks.
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Requests to Google or Optimizely’s servers from the user’s browser will often be blocked under the new content blockers, but requests to the origin are unlikely to be blocked.
The logical solution, therefore, is that solutions that rely on asynchronous requests to third-party domains will release server-side libraries. Along with your JavaScript snippet, you’ll be pasting PHP or Ruby libraries on your server, as well; the JavaScript will send requests back to your own servers, which will then communicate with these third-party services REST-fully.
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For most webmasters, they will rely on their hosts or on WordPress plug-ins to do this work for them. 
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The other issue is scalability. Most web properties today are optimized to serve pages, not to handle and process an influx of analytics data. The new server-side solutions must be simple, reliable and cohesive. If we add dozens of requests and pixels without thinking about performance, as is the case today, we’ll end up flooding our own servers, adding costs and potential latency.
http://techcrunch.com/2015/09/17/the-web-tracking-tipping-point/