When Samantha Lundberg opened Sambuck's Coffeehouse in Astoria, Oregon, she knew that Starbucks was one of the largest coffee chains in the nation. Starbucks Corporation filed a dilution lawsuit, and a federal court ruled that use of the Sambuck's mark constituted trademark dilution because it created confusion for consumers. Not only was there a "high degree" of similarity between the marks, but also both companies provided coffee-related services through stand-alone retail stores. Therefore, the use of the similar mark (Sambuck's) reduced the value of the famous mark (Starbucks).

Note: Can you please answer this question using IRAC( Issue, Rule of Law, Analysis, and Conclusion) format. Because then it will be easy for me to understand the case a a lot better.