I didn't make it clear.

I wouldn't buy "your band's" album, even if I could listen to it right before buying it. I don't have the time to listen to 30 minutes of audio without being hooked onto it first.

One unknown song in my Google Music or Soundcloud auto-playlist may get me hooked... But you need to build a desire to buy the album beforehand.

I don't think I'm the only person like that, btw.

Artists can choose what song plays first on an album on Bandcamp.