This article discusses how memes catch on (or don't) and their impact on culture. The first approach is looking at history as either a narrative or a science. The narrative must be plausible, but not predictable, to be interesting. So too is culture. The things that catch on don't follow a formula per se, but in retrospect they aren't completely out of the blue. The second approach is a comparison with evolution. In this view, it is the glitches that move things forward, not just the formula. The good will continue, the bad will be cast off. However, the line between good and bad is blurry at best, and the very nature of parasitic things like memes is to trick the hosts. The article gives the example of a person with a sweet tooth. If the candy tastes good enough to make the person forget about its negative impacts, it will persist, furthering both the good and the bad qualities of candy. Memes are selected unconsciously and consciously. Even in the case of meme-engineering, in which someone tries to create an idea that will catch on by mimicking what is popular, nothing can be predicted for certain. It doesn't necessarily matter how good an idea is (although it helps), but rather the unpredictable pull of many natural and cultural forces that decides the fate of a meme. Cultural evolution is thus not a direction, but a trend, and not necessarily a very definite trend.

The article touches on a lot of different possibilities, but its tone makes it easy enough to read and digest. The nature of taking the side of unpredictability is that no firm conclusions will be drawn, but the article still discusses numerous possibilities. The question Dennett repeats is "cui bono?" or "who benefits?" He doesn't give an answer, or perhaps the answer is that even if one could measure the benefits, they wouldn't necessarily inform anything beyond that.