Good commentary offers a way for people to sample your mind, to figure out if you are on the same wavelink. To find people who share my values, I want to sample their thinking. The article below is about physical samples, but mental samples count, too!
AdWeek: Sampling Inspires Repeat Purchases, 2009-Aug-4, by Ken Hein:
...sampling programs drove a 475 percent sales lift the day of the event compared to non-sampled households, per the "Report on In-store Sampling Effectiveness" conducted by Knowledge Networks-PDI. Those who sampled an item were 11 percent more likely to purchase it again during the 20-week period that followed.