The sum total of a magazine's potential audience -- usually devised by combining the paid circulations of similar magazines. The assumed universe for literary magazines is in the 750,000 - 1,000,000 range. This said, by marketing to this universe through traditional methods, a decent rate of return would be anything greater than 1%. Therefore, if you sent a subscription offer to the entire universe of 750,000 and your rate of return was 1%, then you would theoretically acquire 7500 subscribers. So while a "potential readership" of 750,000 to 1,000,000 sounds impressive, the true potential gains from this hypothetical universe are far more modest. See audience, reader profile, CPM, audit, list broker, circulation, mass market, crossover market, niche market.