Reverb can add a lot to a track, but it can also detract from a song just as easily. Common mistakes with reverb can be caused by inexperience, such as overuse of the effect, or even by incomplete information. There's no need to buy the most expensive reverb you can find just because it sounds great and has good reviews. There's a good chance that there is a much more affordable option available that will sound just as good.
You can read more here: http://www.audio-issues.com/music-mixing/reverb-mistakes