If video stores that rent and sell hard-core films outnumber adult bookstores by 20 times, and if there are approximately 25,000 such adult bookstores, then simple mathematics says that there are roughly 1,250 adult bookstores. That's a far cry from the 15,000 claimed in your article. Oh, and less than 10% of the number of McDonalds in the country, not the 300+% claimed by your article.
But hey, what's one order of magnitude when you have an agenda to peddle?
26,250 is indeed more than 15,000.