First, a little background: Publishing is a strange business. I don't know any other way to say it. Traditional New York publishing is now owned by six large corporations and publishing decisions are driven almost completely by sales numbers. It doesn't help that so many independent bookstores have gone under, in the face of overwhelming competition from chain stores and online sellers. The large chains set up sales models which were monitored by a very few buyers in a central location. Computer reports dictated what the stores would stock and this largely determined the fate of an author.
The way a book moved through the system was based on advance "buzz" about the title. If big advertising dollars were going to be put behind a title, the chains could justify ordering multiple copies for each of their stores. Publishers paid tens of thousands of dollars for placement of those books at the front of the store (don't think for a minute that some bookstore employee just takes a look through the stock and starts sticking books on shelves and tables---it's all very carefully planned), and that money was spent on the "name" authors and titles.
Okay, so what happens is that First Time Author writes a book and it gets published. Let's say there is a good amount of buzz, some positive reviews, and the author has planned a little signing tour (for all but the top ten or so bestseller list writers, all this is done at the author's expense). First Time Author's book does okay. For the sake of argument, we'll say that it sells 10,000 copies in the first two months. That's not bad. But by then new books are coming along, and the bookstores are allowed to return unsold stock to the publishers (a VERY weird business practice, in my opinion, but that's how it is in publishing). So, maybe 2,000 copies get returned, for a net sales total of 8,000 books.
The author has written book #2 and it comes out a year later. But this one doesn't get quite the buzz of the first. Face it, everyone loves the concept of discovering that fresh new voice! So, this time the chain stores look at their records and see that the author's first book didn't sell out, so they order even fewer copies of the second book--say, 5,000 total. These most certainly won't get placed on a table at the front and, buried among 50,000 other books, will likely not get noticed at all unless the author has really pushed hard for this one. So, probably half of Book #2 get returned and the publisher is thinking this is an author who is definitely on his way out the door. If they give the author a chance at a third, fourth or fifth book, it will almost be a miracle. The computer doesn't lie, and that computer is telling everyone in the publishing world that this author is a loser.
The author still wants to write. There are fans who still want to read their books. But the publisher and the stores are no longer interested. So, if the author is still on good terms with his/her agent after all this, the agent may recommend writing a whole new series or genre and submitting it under a different name.
So, that's the strange world of publishing.
Now, I must say that my own case was not quite this bleak. I was lucky to be with a smaller press in the beginning and they stuck with me through ten books. But when my original publisher changed hands and the interest seriously began to wane I just didn't have the sales to make an agent or a bigger publishing house jump for joy. That's when I began to get those suggestions from agents.
Making a long story just a little bit longer...I came to the realization that the group who were really being left out were my readers. People wanted more Charlie books and I was determined not to quit writing them.
Enter the new realm of e-books, printing presses designed to fill demand as needed--and I was on my way! Now I can write as much as I'm capable of, and I can get them out to the people who want them. To me, it's about the relationship between author and reader. Period. As long as I can come up with fresh plot ideas, and as long as you are out there wanting new books I'll be here!