Logos ought to Implement a more specific "Recommended For You" feature on the website, akin to the way Amazon can recommend books you might like because others who bought books you bought have also bought these books, and the way Netflix can recommend movies to you based on what you have liked in the past, or based on your choices on their preferences survey.
Basically, you build up the profile of an individual -- what publishers they tend to buy again and again, what authors and types of titles they have highly rated in their library -- and then you can make smart marketing recommendations to them whenever they visit the Logos website. You can recommend more books by the same author, or from the same publisher, or on a similar topic, or from a similar theological perspective.
I know that Logos.com and Vyrso both have a Recommendations section that shows you, for any book you're looking at the description of, "Customers also bought" and "Other books by this author" (Vyrso only) and "Other books in this genre" / "Similar Products by Category".
But I'm suggesting that Logos.com (and Vyrso.com) could be even smarter and base its recommendations on what the customer has actually bought and liked in the past, and possibly even a survey of what types of things they are likely to want to read.
