For eight years, Arnold Kim has been trading gossip, rumor and facts about Apple, the notoriously secretive computer company, on his Web site, MacRumors.com.

It had been a hobby  albeit a time-consuming one  while Dr. Kim earned his medical degree. He kept at it as he completed his medical training and began diagnosing patients’ kidney problems. Dr. Kim’s Web site now attracts more than 4.4 million people and 40 million page views a month, according to Quantcast, making it one of the most popular technology Web sites.

It is enough to make Dr. Kim hang up his stethoscope. This month he stopped practicing medicine and started blogging full time.

“In some ways I’ve neglected the site for so long,” he said in a telephone interview. “Now that I actually have a chance to work on it full time, there’s a good chance it can grow more.”