As others have said, the costs of distribution are non-trivial, and are almost certainly a loss for JSTOR on these articles. For example the exemplary arxiv.org, which provides a relatively 'simple' hosting service and where the author prepares the full manuscript- they still have annual running costs in the region of $500,000. Even arxiv.org do not seem to have found it easy to secure funding from other universities and institutions which surely find it essential (most costs are borne by Cornell library).

While there is great value in the JSTOR articles (all published before 1923)- in reality very few active researchers will be reading them. Some of the research will be just plain wrong, some corrected or superseded, and if there is any useful stuff left, then it will be readily found in much more modern and useful presentations.

I think the more important battle is to ensure all current research is deposited in open archives (preferably something like arxiv.org). The historical stuff will surely follow...

If anyone is curious where the money to run arXiv goes, here is their 2010 budget and their business plan.

http://arxiv.org/help/support/2010_budget http://arxiv.org/help/support/whitepaper

That's actually insanely frugal--- $381,000 total budget! JSTOR is very reticent about their budget, but from IRS filings it appears their annual revenue is in the ballpark of $55-65 million, with about $8m of that going as payments/revenue-share to publishers, leaving somewhere north of $40m for JSTOR operations.

It's hard to say how necessary a budget of that size is, made harder by the fact that they publish absolutely nothing about who they are, what they do with the money, how they plan for it, etc. The only source of financial information is their legally mandated annual IRS filing.

There's an attempt to sort some of it out here: http://www.generalist.org.uk/blog/2011/jstor-where-does-your...