Do they really need to rely in manual reporting? I'm pretty sure Shazam has no trouble at all collecting these statistics, and I'd be really surprised if they didn't monetize them.
Location is massively important in searching for a memory. I will forget the dates I was in Europe, but I will not forget that I was there.
I believe cmelbye was simply responding to your "if yes" with a justification for why it's useful. Even if I added the song to my library, what if I don't remember the name or the artist? Will I find it easily amongst the 5000 other songs I've got in there? And maybe I didn't like the song, but I'm reminded of it for some reason and it's really bugging me that I can't remember enough details to find it again. I guess I could listen to every single from every unfamiliar artist I see in my Shazaam history...
Indexing our life events by location and time, paired with a smoother search interface, would dramatically improve the memory augmentation aspects of our personal devices. There are, of course, tremendous privacy risks in accumulating this data (which is why the design tradeoffs / permission system around location services exists in the first place).