After the first quarter, I feel as if I've done reasonably well. I've bought seven books (in six volumes) and spent only $8.50.* My accounting method counts a book as purchased if it has a price, but I cost it at actual cash outlay after credit and coupons. Even my TBR is down, albeit only slightly, at four books.
I'd like to do still better. March was marked by some exceptions, notably Google Play coupons and using up my B&N settlement credit (a very good call, as it happens, as there are reports that Nook Study no longer works for DRM purposes). But it meant that March was worse than February was worse than January, so I have to remain purposeful. However, all purchases this year were wishlist books at a bargain and of which I have reasonable expectations of reading this year.
My bottom line is that my outlay at less than a dime a day was trivial in any sense, but I don't need any new books. I'd like not to buy anything in April at all, but I'd make an exception for a working 90% Kobo coupon.
*For comparison purposes, at this point last year I had bought 15 books and spent $40.