Gianluca Fiorelli explains how "Topical Hubs" have become more important to search engine marketers with the introduction of Google's Hummingbird algorithm, which increases the weight Google gives to semantics and thematic consistency of sites. He believes marketers need a new understanding of semantic technology to better optimize sites for this kind of for search queries, especially conversational query. Think in topics, not keywords, and the connection between them. Here's how.