Have done a little direct mail, personal drop off stuff, related to church work. The experts say that getting ANY response greater than 1 in a 1000 is phenomenal. Obviously, then putting flyers in the post is not a cost effective plan to sell books. --- But you might be thinking to create some other noise. (like what's happening on the site) and any publicity is better than no publicity.
As to the local paper, that's a bit iffier than you might expect. The newspapers in this area are much, much, much more interested in selling advertising than in finding "filler" for their paper. You have reporters and corespondents and wire services, et. al. all providing content. To get even a well written article in the paper promoting an activity of our church we almost always have to do a quid pro quo. They will publish your article if you buy some advertising for the event. (We're talking community events here, not just something for the church.)