I have bought hundreds of eBooks from multitudes of bookstores. I too notice a significant rise in typographical, formatting, spelling, and grammatical errors in eBooks as opposed to printed books. I do not read much fiction. But at any rate there is no reason to try to deny there is a higher percentage of sloppy eBooks than Print books. There are several threads in different forums here that discuss this major issue.

Part of the reason is that many print books tend to have a larger publishing staff of professional editors, technicians, etc. They know their jobs and the tools they use and do a better job than what we see in eBooks. Print publishing companies still don't have a good grasp of eBook development and formatting. Hell, just peek at the formatting of a few eBooks at random and you will see the biggest pile of internal formatting garbage you can imagine. Ebook publishers just don't understand HTML, CSS, etc. and how it should be used to create eBooks. They tend to use a lot of <SPAN> and <DIV> rather than using cleaner, more standardized HTML. I've seen a lot of eBooks that use no <H#> tags for headings. All of their headings are <P> tags with a CLASS id to make it do what a heading tag was designed to do. It is sloppy crap. I also see a lot of <SPAN> tags used to assign formatting and fonts. Again, sloppy. The sloppier the HTML the more likely a formatting issue will occur.

Another reason many eBooks suck compared to their printed versions is that publishing companies don't always keep the digital files they used to create the printed version. When they go back a few years later to create the eBook version they have to quickly and inexpensively digitize the text and then format it for an eBook. This process often produces spelling errors and if they don't thoroughly edit the digitized text we will see these errors.

Obviously there are a lot of self-published eBooks. These are perhaps more likely to have errors as they often are not professionally edited.