The library "front door" model for how you get to licensed content is:
1. Come to library website.
2. Navigate to our links to Elsevier, Lexis, etc. that take you there via our proxy server + authentication.
3. Learn that your library website is the front door.
One side-door access model is:
1. Go to a non-library site that's meaningful to you, e.g., PubMed.
2. Register your affiliation with a library on that site so that it will use the library's proxy server + authentication.
3. Do not learn that your library website is the front door.
Another side-door access model is to do all your research on campus. Just Google stuff and watch it pop up on your screen magically.
Examples of side doors include sites you've heard of like PubMed and Google Scholar. Also EthicShare, Pubget, and I bet many others. LibX is also a side-door tool.
My guess is that these side doors are being built because when libraries make it their business to offer a front door to everything under the sun, some patrons don't really want everything under the sun (at least not every day) and find appealing the idea of a side door to a particular room of the house, a more constrained library of stuff they are interested in, e.g., medical literature.
(Google Scholar doesn't fit that model; it too uses the library model of "everything under the sun," but their market share lets them do anything they want.)
One more thought before I cut off this ramble. It's not clear to me that we front door builders should panic about this trend. I buy the idea that a decreasing proportion of faculty and other advanced researchers care about the library website as front door, but how big is that dip? How do you measure that? Ithaka measures by surveying faculty about their perceptions, not by measuring their behavior. I suspect that many of those advanced researchers (or the grad students who do their article and book retrieval for them) still need the front door from time to time, regardless of how they perceive it. Also even if we're just building the front door for all our patrons minus X % of advanced researchers, that still leaves us with plenty of front door work. Right?
