No-fee open-access journals

"A year ago last month, Cara Kaufman and Alma Wills found that only 47% of surveyed OA journals charged author-side fees (see pp. 1, 44, and Table 30). 

http://www.alpsp.org/publications/pub11.htmTo me, this was a little like the first human sighting of the Antarctic land mass in 1820:  proof that a huge terra incognita existed just over the horizon, awaiting exploration. Only a minority of existing OA journals actually used the most-studied and most-discussed business model for OA journals --charging author-side fees.  (Let's call these "fee-based" OA journals.)  The majority of OA journals turned out to use business models that had rarely been acknowledged, let alone studied.  (Let's call these "no-fee" OA journals.)  We thought we understood OA journals but we only understood a subset, and the greater part of the whole was still largely unknown. I wish I could tell you how many different ways the no-fee journals have found to pay their bills, and which methods work best in which disciplines and countries.  But I can't.  No one has done the studies yet.  A few ships have approached the coastline of this land mass but we haven't come close to penetrating the interior or producing a map. Some no-fee OA journals have direct or indirect subsidies from institutions like universities, laboratories, research centers, libraries, hospitals, museums, learned societies, foundations, or government agencies.  Some have revenue from a separate line of non-OA publications.  Some have revenue from advertising, auxiliary services, membership dues, endowments, reprints, or a print or premium edition.  Some rely, more than other journals, on volunteerism.  Some undoubtedly use a combination of these means.  But we don't know how many other sources of revenue might be missing from this short list.  We don't know how many no-fee journals use which method, and we don't know how the methods compare with one another for financial sustainability...."