Gladwell suggests split-seconds decisions are better than the decisions where we take considerable time to weigh our choices and options. He points out that our mind figure things, people, et al. in a blink of an eye. And it is often that these snap judgements are much more trustworthy than judgements arrived at rationally. But he does not stop here and goes on further: snap judgements can be misleading, too; he termed it Warren Harding error. He suggested that there are some instinctive processes that prevent us to see clearly; and hence cloud our judgements.
Blink is an interesting read. It is very well written, and at the same time engages your attention from the start. And writing is reader friendly, perfectly suitable for a layman.