Social question and answer (Q&A) sites receive tens of thousands of questions each day, producing a mix of archival information, asker satisfaction, and, sometimes, frustration. This paper builds upon several recent research efforts that have explored the nature and qualities of questions asked on these social Q&A sites by offering a focused examination of answers posted to three of the most popular Q&A sites. Specifically, this paper examines sets of answers generated in response to specific types of questions and explores the degree to which question types are predictive of answer quantity and answer quality. Blending qualitative and quantitative methods, the paper builds upon rich coding of a representative sets of real questions - drawn from Answerbag, (Ask) MetaFilter, and Yahoo! Answers - in order to better understand whether the explicit and implicit theories and predictions drawn from coding of these questions was borne out in the corresponding answer sets found on these sites. Quantitative findings include data underscoring the general overall success of social Q&A sites in producing answers that can satisfy the needs of those who pose questions. Additionally, this paper presents a predictive model that can anticipate the archival value of answers based on the category and qualities of questions asked. And this paper offers data suggesting significant variation in the patterns of use and types of questions that characterize each site, with, for example, Metafilter's Q&A community exhibiting a strong bias toward answering factual and prescriptive questions (i.e. questions seeking an existing solution to a recognized problem or challenge) while Answerbag's community shows a bias toward social and conversational questions and answers. Qualitative findings include an analysis of the variation in responses to questions that are primarily seeking objective, grounded information relative to those seeking subjective opinions. Additionally, we offer possible reasons for Metafilter's striking success (relative to its peers) in producing answer sets that are likely to be judged as satisfying the questioner's needs and as having significant archival value. While these metrics do not suggest that Metafilter is the "best" of the three sites, our findings do point towards Metafilter's focused community as offering distinct advantages for certain types of question and answer exchanges.