Well, if you really devote yourself to it, you can flower a very surprising number of plants in a largish bedroom, and put one or two of your male clones in there (the same clone, duh) and you can get quite a large number of seed packs from different moms, but not necessarily large enough to sustain the demand. A lot of space has to be devoted to keeping clone moms, testing thereof, and not to mention all the growing that goes into finding a good male. Plus, yield will mostly determine how many seeds you get, so that will vary from strain to strain, with the most popular (OGs) being among the lowest yielding. Sometimes he does larger runs, I know he made a fuckton of Goji and it still sold out pretty much everywhere.