Having fun with online personals

Other than business and travel or bookings internet is a great place for fun and free time enjoyment.
So what is the most successful and popular usage of internet on the fun side.
We all know porno, travel, news, content sharing (pictures and videos) are the main areas but looking at statistics, general and by country, you will discover that dating sites (including personals, chat rooms, encounters) are always at the top positions.
As a fact today singles' dates and adult personals websites are the most popular ever free time websites.