Obviously, very few people were literate in Nero's Rome and it was a long way until the printing press was to be invented. So what did a bookstore in the Ancient Rome look like? What kind of selection was there and where did it come from? Who was transcribing the books? How affordable was an average book? Was it similar to today's situation when most books that come out are quickly forgotten? What kind of clientele visited such stores?
I thought I saw a more recent answer to a similar question, but nothing comes up...fortunately there are some older answers that should be helpful:
How was Caesar's "Gallic War" created and distributed? by u/XenophonTheAthenian
And one that's very old now but still relevant: How were plays and other literary works published and distributed in ancient Rome? by u/aescolanus
In case somebody finds this post, here are two interesting articles that I've managed to find through my own research and that answer some of my questions.
https://www.historyofinformation.com/detail.php?id=4051
https://spartacus-educational.com/ROMpublishing.htm
In case you want to skip straight to the answers, here's my TLDR:
So what did a bookstore in the Ancient Rome look like?
Bookstores in the Ancient Rome were considered ordinary luxury shops and would function very differently from today's bookstores. To begin with, books didn't look like our books today, but usually consisted of several "volumes" (rolled up parchments or sheets of papyrus) glued together, which made them quite expensive and prone to rot and damage in general. As printing press didn't exist at the time, books had to be transcribed by hand and wouldn't commonly be published in large batches like they are today. Instead, most people would acquire their copy of a book by having their slave transcribe the book in question on demand. Bookstores then served as more of a meeting place for the literate aristocracy, where they would discuss literature, and their importance as a way to distribute one's work only grew in later Rome, when writers desired to spread it outside of the circle of their acquaintances. Also, authors would not be paid for copies sold as they are today, but instead the money would all be kept by the bookseller, as they were the ones actually making the copies.
What kind of selection was there and where did it come from?
Even though I wasn't able to find out how large a selection a typical bookstore would offer, there were apparently many books that didn't stand the test of time and have been forgotten for their poor quality. Nonetheless, the books would come directly from the authors, who would typically give a copy of their book to the bookseller for free.
Who was transcribing the books?
The slaves, of course. To speed up the process of copying, a reader would sometimes read the book out loud to the other slaves, so that many copied could be made at once.
How affordable was an average book?
In the articles above, there is only one mention of a price of a book and it was five denarii. Apparently, such a book would be unaffordable for the average Roman, but it hardly mattered anyway, since the only people who could actually read were the rich aristocrats.
What kind of clientele visited such stores?
Again, it was mostly the rich aristocratic intellectuals and scholars.