Give the readers a little more time
I'm probably coming late to this party, but just noticed the Boston Globe has restricted its archives so that only today and yesterday are free. While I think it's perfectly fine to charge for archives, at least give the readers a chance. Leave articles open for five days or a week -- about the time it takes for me to take this week's pile out to the garbage. That seems to be a reasonable compromise.
Is that inconsistent with my musings on whether some forms of journalism ought to be pay as you go? Not really. If you are going to allow free access, then allow reasonable time for people to read and think about it, and perhaps come back to it. That's different than knowing upfront that I, as a reader, will have to pay for all versions of specific content.