Not unheard, of, no. The only problem is that huge series, tend to consist of several small novels, all of which are horrible, contain no emotion, and, of course, buying the whole series would be at least $300 at ten bucks a copy. Now, that doesn't mean your novels will have no emotion or no feeling or no plot. This isn't about your series. But that doesn't stop the other 70% of long series' novelists to mess up the image for you and create a bias surrounding humoungo series. There are thousands of books out there. Unfortunately, I will not live long enough to read them all. Because of this, I do what most people do...I skim novels, read the back, maybe the first paragraph, check out the cover illistaration, ect. This is meant to allow a reader to pick up a novel to read with an okay chance it will be worth it. I tend to use the "not pick a book from a series over 12 books" rule simply because they are usually horrible, and I don't want to have to read thirty or forty some books to get to the point! It usually means there is too much description or repetitive sub-plotting. Life is too short and I want to taste several plots before I die. There isn't a ton of originality out there, so unless you have a phenominal series I would much rather read Betsy's Trilogy, than Andersons eighty book series. I don't want to get half way in and become uninterested and have wasted all my Time. I recently read too horrible boooks. I lost around three hours of life. Imagine ruining two months of time! Not to say yours is horrible, so because of these thoughts it is unlikely I would read your series unless everybody was like "OH, MY GOSH! YOU HAVE TO READ THIS!" So, you will be faceing the facts of life that because of bias, time constraints, ect. you will have to write, like, some incredible novel from another world if you expect a ton of people to read it. For this reason, editors, publishers, will not be overly interested, unfortunately, unless it's really good and original....even then it's a risk. Sorry. Try getting people interested in just one book, without saying to the world this iS a huge series, and if you get them hooked, maybe they'll follow you.