I have always believed its best to share what you read. Since the early days of my blog I have made my subscription list transparent as my blogroll. What I read is a time commitment, a real reflection of my social network. Naturally, what I read hovers around 150 blogs because that's all my brain can take.
Daves's subscription commons uses pooling to create network effects. Its actually very similar to FOAF efforts like Plink, as many auto-generated FOAFs come from OPMLs, although nodes aren't people, but with the added benefit of finding what writers are reading.
