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. Kim’s website 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 websites.

It is enough to make 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.”

Kim epitomises the home-grown publishers whose wealth has been enabled by the Internet. Although few of the millions of blogs ever make their creators rich, the ones that do provide all the incentive necessary to fuel the medium.

A question Kim often fields from friends and associates is, “How does that make money?” He answered the question in an entry on his personal blog last month. It can all be “boiled down to one simple accomplishment: building traffic,” he wrote. “That’s it. If you have a site that attracts a lot of visitors, you will be able to make money. On the Internet, traffic equals power, which subsequently equals money.”

When Kim, who lives just outside Richmond, Virginia, began blogging about Apple in 2000, the word blog had not entered the lexicon. Creating anything beyond a bare-bones website required programming skills and tech knowledge. Kim, a computer science major at Columbia University, had the know-how. He also knew that almost everyone enjoys an advance look at future products.

He envisioned MacRumors as an aggregator of all the rumours and hints that appeared on message boards and other websites. “The rumour reports have probably been more right than wrong over the years,” he said.

Given Apple’s penchant for secrecy, the company inspires a lot of speculation in the technology industry. Apple enthusiasts dissect every product rumor the way political pundits do political sound bites.

As one of the original websites about Apple, MacRumors was well positioned to become a destination for users and a clearinghouse for gossip. MacRumors “knows more about Apple than Apple management does,” the blog 24/7 Wall St declared last spring.

The site placed MacRumors No 2 on a list of the “25 most valuable blogs”, right behind Gawker Media and ahead of The Huffington Post, PerezHilton.com, and TechCrunch. Two of the other tech-oriented blogs on its list, Ars Technica and PaidContent, were sold earlier this year, reportedly for sums in excess of $25 million.