There has been an interesting and increasing trend among Smashwords authors and publishers of Young Adult fiction to price their newly published eBooks free for an initial introductory period, and then raise the price. The initial free eBook period varies, but it would appear to be as short as one week in some cases to a few months in other cases. With this site being updated only once a week, it is not possible to keep up. So, the recommendation is to have a look (here) through the newly published free eBooks frequently, and if something looks interesting, then grab it. It may not be there for long.
Please note that regular weekly updates of this blog will resume in late August. To readers of this blog in the US and to Americans overseas, Happy 4th of July.