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One model I've seen that seems to work goes like this:
Part of the article is viewable, but that part is also kinda able to stand alone. At the bottom of the article there's a "Read More" tab. You are allowed to click through to the rest of the article below the fold for free... say 5 times per month (resets every month). After those 5 clicks, you are prompted to subscribe if you want to "Read More" (in this particular example I think it was $2.99/month-by month or $21/year).
I never saw Baker's site after it went behind the wall, but I understand it was similar.