I've been a publisher and acquiring editor for years, although never with a company that does this sort of thing (nonfiction lifestyle and business are my fields of expertise--and quirky pop culture stuff is my love as a AE). However, according to my agent, memoirs--or at least personal stories, which can be a bit different--are really hot right now. So, as long as it's a fascinating story with resonance for a wide range of folks, it may well be the sort of thing people are looking for. Some examples:

Story of overcoming personal tribulations, disability, etc.--has resonance for those experiencing these things, also speaks to the natural
human desire to read tales of triumph.

The "regular guy" who is witness to extraordinary events, or has known remarkable people. Whom did he rub shoulders with in his life
and career, what did he think of them, how id they affect him?

The personal story that helps us understand something bigger. Like David Denby's book about reading the great books of Western
Literature--it's a personal memoir, but it helps us see the literary canon anew.

In order to successfully pitch his book, he needs to ask himself questions along the lines of (note--these are the questions I would ask as an Acquisitions Editor, or if I were thinking about taking something on as an agent):

What is unique about my story? Why do people want to know about me?
Who is the target demographic for this book? What else do they read and buy? How does my book fit in with those books and products?
What will people learn from this story? How will it change and move them?
What's the competition? What other books like this exist? How well have they sold?

The cover letter should address these questions, succinctly and in a very market-oriented way. If a publisher takes this book on, that house will spend at least $100,000 on plant, printing, and marketing. Probably a good deal more. Question #1 is, will it earn out, battling for supremacy with Question #2, is it good? No one wants to publish a crap book that makes millions, but that's better than a brilliant one that collects dust in the warehouse. Let's take it as a given that the book is brilliantly writer, a page-turner, something that makes you yearn to know more once you read the first page. The question then becomes, how do we market this in such a way that at least 40,000 people (a decent but not stunning first print run, to earn out the plant and PPB costs) will agree.

Without knowing the "meta" story, I can't really suggest houses. By meta-story, I mean, what is this book about besides one man's life. As he's an English professor, is the story about university life and how it's changed over the years? Is it the "one man's triumph over adversity" story noted above? Is it about modern students and how they differ from students of yore? Is it an Updike-esque romp through sexual and social mores of upper middle class academics? Or . . .?

What's the elevator pitch? You know, you get me alone in an elevator and you have to make me love this book in 1 minute between floors. "Crazy whack-job sea captain is obsessed with great white whale, nautical highjinks ensue" . . . "One neurotic woman's journey through the sexual liberation on the '70s and her quest for the elusive 'zipless fuck.' " . . . "Supercomputer goes crazy, kills a team of astronauts--except one, who disables the computer and ends up in a mysterious alien apartment." You know. That kinda thing. Sadly, few publishing folks have time to read a whole manuscript before giving it the thumbs up or down. We read the cover letter, check out the demographic research and market positioning statements, see if we agree that the world needs this book, and then take a quick flick through to see how well written it is. If it's brilliant, and the market research seems to show this is one people want, then we'll ask for more material.

Oh, and how mediagenic is he? If it were a success, would he hold up well on Colbert, Good Morning America, etc.? That's a consideration too. Sometimes I'll be on the fence about a book, but if the author is a tireless self-promoter, and fascinating to talk to, it'll tip the decision because I know he or she will be able to see books just on sheer force of personality.

Hope this helps!