It is not, nor has it ever been, the job of a library to help people promote books. Libraries exist for the benefit of their communities. When they do invite an author to speak or whatever, it is not to promote the author but because the community has expressed interest.
A better tack would be to see if they will let you rent (or use for free) space in the library to host a discussion. What are you an ‘expert” on? For example, you could hold a discussion on how to publish to Kindle. The library would be more open to that, because it would be a subject that would actually attract people to come to the library.
Bookstores are only going to be interested in hosting author book signings for books they actually stock AND authors who will attract readers into the store. Again, it is not the job of a bookstore to promote you. It is the job of a bookstore to get people into the store. Unless you can present to the bookstore a plan to attract people to them, they can’t be bothered.
That said, look into local book fairs and conventions. These are excellent places to sell because these are captive audiences that specifically go to shop. I have always had very good luck with these sorts of events. Folks who attend these events don’t care indie versus trad…they just like to meet authors.
What I normally do is:
Have 20 books per title plus 1 book for every 20 people expected to attend the event. So if the event normally attracts 500 people, you have 45 books.
Do not put the entire inventory on the table at once, and do not have even stacks of books on the table. You want the table to look “full” but not untouched. Uneven stacks gives the impression of sold books.
Have a bowl of candy on the table. Seriously. It is like a magnet. People stop instinctively to grab a piece, and then feel obligated to at least look. And when people see other people milling around your table, it again triggers a visual cue that something interesting is there. (I suggest sugar-free hard candies if it is an outdoor event because chocolate melts).
Have a prize. Give away raffle tickets to each person that stops at the table, and at the end of the day you hold a drawing for the prize. Generally, I make a small prize basket with swag I produce using Cafepress.com. Make sure you tell the event coordinators you are doing the giveaway, as often they will announce it for you.
Use special pricing that is a round number. Round numbers are easier to deal with. If the print book normally sells for $14.99, offer it for $10. If you are responsible for sales tax, set the price at a number that includes the tax already to make life easy. For example, with NJ 7% sales tax, I would use a price of $9.35 + .65 tax = $10. The easier you make it for people to pay, the more likely they open their wallets.