I'm more satisfied with Audiobook Builder than I've been with any shareware I've purchased in years. So far, Audiobook Builder works exactly as the developer claims, and best of all, it seems to have a 100% success rate in joining mp3s. I've already converted a dozen books. The feature set is maybe a bit limited and the program is not exactly speedy, but everything it does functions perfectly. Best of all, the chapter creation function could not be simpler. I have an enormous audiobook collection, but my iTunes and ipod were becoming littered with thousands of mp3 files, which was annoying and impractical to say the least. For the past year, I'd been struggling with Join Together, which only worked about a third of the time, and with Join Together, I could never chapterize my converted audiobooks because Join Together requires the use of Apple's Chapter Tool (which--strangely--I was never able to find on the internet). Anyway, when I discovered AudioBook Builder, it came as a godsend and it was the best $10 I ever spent!