Evgeniya, While not yet published, may I suggest research that was accepted for AoIR 12.0? Unfortunately, finances prevented me from presenting the research in Seattle, but after reading your question, I thought my study may be helpful, though it's less specifically about macros and viral images and more about a specific kind of meme, the nuclear meme. My research is accessible here: http://theoplothe.com/meme/index.html Theo Plothe MA COMS - New Media & Technology/Social Networking Northern Illinois University