Cultural evolution - a byword for evolutionary and cognitive approaches to human culture - can provide a useful framework to understand how information is produced, transmitted, and selected on the web. Human culture is cumulative, meaning that it increases in complexity and efficiency from one generation to another, drawing on past innovations. Cumulation, however, differs depending on the specific domain. Two features of cultural systems impact the velocity and the robustness of cumulation: availability, i.e. the number of possible cultural traits one has access to, and fidelity of transmission, i.e. the degree to which cultural traits are preserved during transmission. I will discuss how the diffusion of online digital media increases both availability and fidelity, thus boosting the potential for cultural cumulation, possibly in domains where it was before limited.