The answer is simply money, combined with recent success. Any team reaching the championship game is going to be big with recruits. Doesn't hurt that they probably have great recruiters and coaches. But at the end of the day, the answer is simply dollars and cents. I'm not talking about boosters paying their athletes (although it might be happening - Troy Smith was suspended for two games, the 2004 Alamo Bowl and the 2005 season opener for accepting $500 from a booster), my main point is they simply have a larger athletic budget than other schools. When you have
$104.7 million in annual revenue and can spend over $100 million of that for facilities, equipment, etc., it's going to be a huge draw for athletes. They can afford to build arenas comparable to NBA or NHL venues, and have the student body and alumni base to fill them on an every-game basis. JP has said it over and over, college athletics is more and more like a business, and you need to have CEO's running everything.
My source, and an all-around excellent article done by USA Today on OSU athletics:
Why Bigger is Better at Ohio State