Its amazing that a company whose main product is search has such a worthless search for their store. Its absolutely worthless unless you already know exactly what you want.

You have to use their general search product to find enough info to bring up the exact title you want to buy.

For example you can't on the play store find all the oreilly books that aren't drm encumbered or find all the books on a certain topic in a certain range of years directly via its interface.