Harry - 7:58 pm on May 6, 2012 (gmt 0)
It's a mix bag. Some apps and plug ins take away from us, but others add. For example, a Stumble Upon / Reddit adds visitors. A Facebook commenting system may siphon users away. Nothing is clear. It's a case by case analysis and having the foresight to pick the right solutions that fit your audience and what your site is about.
Curating contents and access to our content is also part of our work as webmasters.