The author of Open Court, CC here on the boards, might chime in. I'm sure she has personal experience!
I'm just seeing this now, so sorry for the delay.
If your's is a self-pubbed e-book you might want to solicit help from other self-pubbed people here for more ideas. Mine was traditionally published with Knopf, so I don't have a clue about self pub promo, but...
The best thing I did for my book was to email the USTA and ask if I could send them a book and possibly have it mentioned in their newsletter. They put in a blurb and that spiked a few sales for me. I found the email on their website, so it doesn't hurt to ask.
My own efforts of trying to contact tennis magazine publications and offer them arcs didn't do much. I often didn't get a response. The marketing person from my then publisher had so many books to deal with that if something is extra work like that, it often goes undone (not from malice, but because they have a tendency to only do the normal arc route).
I also sent postcard notifications of my book's release to, literally, hundreds of different tennis academies and organizations -- there are tons of junior tennis academies and camps and that's what my book centered on -- but it really didn't reap results the way I'd hoped. Some organizers were excited about this book from Knopf and contacted me -- only to ask for FREE books for their entire junior tennis leagues and the like.
Locally, I went to different country clubs in the area and gave them stacks of postcards with the book info, and talked up the front desk people to say I was a local author and offer (one) free arc or book, to try and make it known. Did that work? I have no clue.
When Barnes and Noble skipped my book, I went to the local B&N's (where I routinely shopped) and introduced myself and asked if they'd consider stocking it. They didn't. I gave a copy to the local paper (I live in a mid-sized city) and it was mentioned in a small book news sectionl ALONG with others' self pubbed books, with no disctinction that mine was traditionally published. After that newspaper mention, a few copies were stocked at bookstores, but they didn't have a traditional cover -- but the cover picture imprinted -- so my photo or info wasn't present??? Still trying to figure that one out.
It was all pretty disheartening. I think some people are great at marketing themselves and I think I'm not one of those people. But I don't say this to discourage you. The great thing about self-pubbing, I imagine, is you don't have to worry about your book being out of print. There was a sense in me that if I didn't do everything I could think of the book would go out of print before it had a chance (which is what happened.)
Do what you can. You've worked hard. Good luck! The book sounds fun and I like the title!!