This requires a strong dose of faith from the customer. Printing is customized manufacturing - every job is new. Going online to buy books that are already manufactured is one thing. Going online to arrange for the production of unique materials is another. Getting anything printed well requires tight orchestration between the client, designer, and printer.
Good printing is as much about preventing mistakes as it is about high-quality craftsmanship.
You can build a professional relationship that will serve you for years. You have more control over your printing if you and your printer know each other. Potential printing nightmares are discovered all the time in a prepress department. Prepress operators are often on the phone with customers, helping them fix current problems and prevent future ones. Consumers turn to printers for all sorts of help with paper, file preparation, ink problems, scheduling, and mailing issues.