Some authors want to use their self-publishing success to leverage into a traditional publishing deal. For years I tried to find out what that "magic numbers" was. In other words, how many self-published books must you move before it's worth mentioning on your query.
I read everything I could, I asked agents and authors at writing conventions and never could find out what the magic number was.
I think I have it now. It's 5,000 books over a one year period. I came to this number because of two sources.
One was at the DIY (Do it Yourself pre-conference to the BEA) a few Saturday's back. 5,000 was the number that was expressed at the luncheon session by Arielle Eckstut, and David Steery, Co-authors, The ESSENTIAL GUIDE TO GETTING YOUR BOOK PUBLISHED. This is an excellent book by the way. I've read many on the subject and poo-poo most of them but I really liked and got a lot out of this one and think the authors did a fantastic job and have a good deal of knowledge to impart.
The other I ran across in a forum that was discussing whether self-publishing was the kiss of death for authors. Many of those answering said yes. I heartily disagree and think it can be the launching pad for you (it was for Michael's six-figure deal). And one person found a great link from a Forbes article this last October. In it the founding partner of at Levine Greenberg Literary Agency (among the top five overall most active agencies in the business, according to Publishers Marketplace) said "If the author has sold 5,000 copies in the previous year, it interests publishers. And if an author has sold that many, she or he probably has some sort of platform.” You can read the full article here.
A few other data points on the subject. The Trident Group has recruited a number of self-published authors from Kindle Boards for representation and Noah Lukeman (one of the largest agents in New York) approached and signed D.B. Henson. He also signed a self-published author J.R. Jagger but I don't know if J.R. submitted to him or if Mr. Lukeman approached the author.
There was a time in the past, where it was highly recommended that you don't self publish if you desire a trade publishing deal. Much of this centered around the fact that the 'first publication rights' were broken. I try to keep my finger on the pulse of this type of attitude in regards to the industry at large and I don't see that being such an issue these days. In fact, at the BEA many agents and publishers on panels mentioned that they are attracted by self-published authors with a proven platform. When self publishing was relegated to print, and sales were low, it was difficult to build much of a platform. With ebooks authors are finding audiences all the time and from my perspective (and what I've read from those in the industry and on panels) this is currency in the new model.
I mentioned this on AW and not surprisingly many disagreed with me. Many there stated that if the first publication cherry was burst - it was somehow now "untouchable". Other pointed out that since most self-published authors don't ever sell much it's not worth the risk for those who might still care. Are they right? I don't think so - but I want to at least present both sides. If you are thinking of doing this and want to hear the other sides here are some recent posts on AW to see what others have said.