While spam musubi is popular all over the world, it's particularly beloved in Hawaii. The state's high consumption of Spam is well-known, with Hawaiians eating more Spam per capita than any other state in the US.
There are various theories about why Spam is so popular in Hawaii. One explanation is that Spam was widely available during World War II, when the US Navy had a strong presence in the islands. Another is that Spam's saltiness pairs well with the local cuisine, which includes a lot of fresh fish and produce.