And I wasn't alone. He discovered Bujold, Weber, Flint and Ringo and encouraged thousands of others. With so many publishers moving towards agent-only submissions, Jim went in the other direction. He introduced an electronic slushpile and made it easier for people to submit. And set up a free online workshop on Baen's Bar where authors could post their novels a chapter at a time and receive feedback from fellow workshoppers. And it worked. Authors made it from both the slushpile (of which I was the first) and even more from the workshop.
And Jim didn't stop there. In the case of John Ringo, who had his novel rejected by a slush reader, Jim took the time to read the ms, explain to John why it had been rejected and how it could be fixed. John took the advice, resubmitted and, several NY Times bestsellers later, the rest is history.
Much has and will be written about Jim. David Drake says it better than most here: http://david-drake.com/baen.html
But what I think made Jim Baen unique in the SF field is the way he turned Baen from a publishing company into a brand. There are bigger publishers than Baen but only Baen has a fan base, and creating and nurturing that customer loyalty is an incredible achievement. There are thousands of readers who buy Baen books not necessarily because they recognise the author but because of the Baen name - if Jim published it, it must be good.
And how did Jim do that? I'm sure they're are many opinions but here's my take. He did it in two ways. First, by concentrating on publishing books he liked to read - ones that were heavy on story and entertainment. And, second, by connecting with the public.
Accessibility could have been a Baen watchword. Jim was accessible - anyone could have his email address or walk into Baen's Bar and talk to him. His books were accessible - no encryption on ebooks. Whereas other publishers might post a sample a chapter or two of their books on their website, Jim would offer a dozen or more. And encourage his authors to snippet widely and often. And give their books to the free library after a year or two for free unencrypted download by anyone in the world. Or give the book away on a promo cd slipped inside another book.
Jim had the ability to make everyone feel involved. Baen was a family with many children. And Jim would listen to them all. If you had an idea - a favourite book that had gone out of print, a novel inside you bursting to get out - he'd listen and if he liked the idea, he'd run with it.
There are too few people like that in the world. Today there's one less.