Susan Blackmore's book, The Meme Machine , offers a solid, broad, and very ambitious introduction to the subject. Memes can be considered the determinants of culture, successfully reproducing themselves and adapting to their surroundings to insure that they can continue to reproduce. Memes are often compared to genes. While there are differences in the nature of genes and memes they seem to evolve similarly in many respects. In other words, a good replicator must be copied accurately, many copies must be made, and the copies must last a long time.
Genes are very successful replicators.
As it turns out, so are memes. Memes, it seems, are quite a grand theory of almost everything. Certainly there is a great deal of plausibility to the interpretation she offers. Among the larger problems with memes is in defining just what they are. There is also little understanding of how memes replicate themselves and what determines whether a meme will be successful or not.