When nearly everyone offers products for free (besides Microsoft) or just as downloads, for ad revenue.Linked In has been a pioneer not just in professional social networking , but in its pricing strategy. This has enable it to keep it a very loyal base, beat off lots of challengers , and command a 1 Billion valuation.
I find that sometimes people who charge you a transparent fixed fee , are better than people who sell your identity to lots of advertising companies but charge nothing. Both free pricing (with zero privacy) and expensive monopolistic /early bird premium pricing are bad pricing strategies for retaining customers . Here is much more renowned blog that argues that google analytics is much more expensive despite being free (http://www.mymotech.com/google-analytics-can-be-more-expensive-than-webtrends/)