Optical afterglows have been detected for about 1/3 of the rapidly-, well-localized gamma-ray bursts. This data-rich subsample of the rapidly-, well-localized bursts has naturally been the focus of the vast majority of the field's attention and resources over the past four years, but in the end, it is a biased sample. The nature of the so-called 'dark bursts' has only recently become a subject of greater interest, and as might be expected given that these are by definition data-poor events, contradictory initial findings. We try to resolve some of these questions, and argue that, with the exception of perhaps a few bursts, the dark bursts are most likely the result of circumburst extinction. We discuss implications for the nature of the circumburst cloud, and star formation in the universe.