Kindly Explanation

On this Valentine's week, Facebook Data Science runs a series of blog posts about love. Behold the power of modern data-collection and analysis: listing the cities that have the "most single males to single females" (San Francisco is #1) is a trifle; Facebook can tabulate the actual rate of couple formation:

Facebook, with 201 million users in the U.S. and Canada, has something the Census Bureau doesn't: Real-time relationship statuses for about half of Americans. Over a one-month period, Facebook ranked major U.S. cities according to the percentage of singles that went from "Single" to "In a relationship."

Digging deeper, the Facebook data miners looked at the number of times each member of the couple posts on the other's timeline:

During the 100 days before the relationship starts, we observe a slow but steady increase in the number of timeline posts shared between the future couple. When the relationship starts ("day 0"), posts begin to decrease. We observe a peak of 1.67 posts per day 12 days before the relationship begins, and a lowest point of 1.53 posts per day 85 days into the relationship. Presumably, couples decide to spend more time together, courtship is off, and online interactions give way to more interactions in the physical world.

As many married people can attest, intra-relationship communication can go down over time. The FB data analysts are positing a kindly interpretation--more "interactions in the physical world".  Well, it's Valentine's Day, when all explanations should be kindly.