The long tail has been frequently discussed with respect to online companies. The idea is simple: yes, there are lots of very popular things (like, say, Lady Gaga or Justin Bieber), but there are actually a lot of people with specialized tastes (for example, computer nerds like Jonathan Coulton). The internet enables those specialized interests to take root: on the local level, fans are isolated, but combine people nationally or internationally and you can get big business. Amazon and Netflix are often credited for having taken advantage of this: Amazon because it can sell lots of books that local bookstores can’t carry, and Netflix because it can have lots of special-interest DVDs. The online program Art of Problem Solving, for students with talent and interest in mathematics, is quite similar: it creates a mathematical community that can’t exist locally. Other forums, Twitter, Facebook, LinkedIn, etc. do the same for other fields. And magazines with national distribution fill the same niches, even moreso prior to the internet.
Summer programs that draw statewide or nationally can provide much of the same advantage. Programs for students with interest in particular academic fields (from mathematics to writing to astronomy) allow communities to form based on these common interests. Without the inter-school draw, there would not be enough students to create these communities. (The same argument can be made for programs for students with learning disabilities, for sports, etc.)
My view is that these opportunities are crucial to developing young learners. There should be systemic support for exploring your interests. Schools alone cannot offer this support, because they don’t have the staff or the size to take advantage of the long tail. Hence, we must have stronger support for summer programs that can bring students with common interests together, and also for programs like Splash that draw across schools, where the variety encourages students to find their part of the long tail. (I also admire Citizen Schools for the same reasons: they encourage students to deeply pursue new interests, although because they are within a single school it’s not always the case that everyone in a project is deeply invested.)
Which brings me to the discussion recently about “expanded learning time” (ELT). The discussion is here and here, and the participants quite nicely talk right past each other. In a bid to share some of the contradiction myself, I am both a strong supporter and opponent of ELT.
I am a strong supporter when ELT means exploring and developing new interests. But I am not a supporter when it means, simply, more time learning the way you do in school. I don’t believe that additional time addresses the root problem that students do not self-identify as scholars, and it is a tremendous missed opportunity for students who cannot explore their part of the long tail.
While I can appreciate arguments that students should not choose their in-school curricula (because there are basic things that they should know), I firmly believe that ELT should center around choice and following your interests. Summers, weekends, and after-school programs provide fantastic opportunities to do so. We should make it expected that students pursue these opportunities.
Consider Learning 
Great post, Dan. The thought of an extended school day where students just do more KIPP-like drills is appalling.