Probably not by the web crowd, but I have heard of them used in big data situations. I don't know whether cache-miss is still a primary factor, as really large

Probably not by the web crowd, but I have heard of them used in big data situations. I don't know whether cache-miss is still a primary factor, as really large data-sets simply don't fit in memory without a trie. Any scalable type-ahead search uses one - type something into Google's search box and imagine the size of the search space. Additionally, the completions displayed are sorted by frequency, so imagine keeping that up to date as people enter more queries.