Image credit: parl
About a year ago this trend started with Plaxo when they launched their redesign. This was shortly followed by LinkedIn and a couple of weeks ago by Facebook with their latest redesign. Now also Friendfeed is part of the 'larger' font community. Of course I don't know the rational behind all these redesigns, but I do have a couple of theories
1. All social communities want to attract a larger group of people. This does however require the capabilities to attract different demographics. Facebook is the best example, founded in the college going age group, but now growing the fastest in 35-54 age group. Designing for this older age groups requires larger fonts to please their eyes.
2. Larger screens are easily and cheaply available. We have 3 on our desks and need to be able to read the information from a larger distance. We are too afraid to miss something. The different communities recognize this and anticipate with larger fonts.
3. The Tech Bloggers whose opinions are critical for success are becoming older and do start to require reading glasses. The larger fonts are an attempt to ease their reading and create a positive opinion.
You got any other ideas?