Sadly, the "buy from FM" feature quickly reminded us why we can't stand music radio, and while we could easily get the meta data for the station we tuned to, specific (or sufficient) song data was more rare -- on our fourth or fifth try we finally nabbed Rod Stewart's Maggie May, and the actual download process was painless.
In 2002, a test by Sandia labs in the US found that a similar dowsing rod device, called the Mole detector, did not work and performed "no better than a random selection process".