You show some ignorance with regards to how comicbook shops work.
For starters, nobobody has any kind of numbers on how many issues are actually sold to individual readers of any book.
All we know is that retailers ordered 60K, eh, no, 76K of the first issue.
And roughly the same number got ordered of the second issue (which is abnormal in itself because usually the numbers drop about 50% for second issues, no matter what the book is or who is on it).
Early New 52 books being returnable may have had something to do with it.
Of course, all these orders happened 3 months before the first issue even came out. This is how it always is. Usually #4 is the first issue that the retailer can do more about than guess how many he'll be able to sell, which is where you usually see books to start levelling off. The Finches, 11 issues in, are still in wild freefall.
Anyway, you say less than 50% stuck around to read Azz's 36 issues? About 50% has stuck around to read even the first 10 issues of the Finch's run.