In recent years their legacy has extended beyond the Netherlands, and the group is today recognized as a distinctive exemplar of the garage rock genre.

Unlike many European bands influenced by the Beatles, The Outsiders took their cues from harder-edged British groups like the Pretty Things (who frequently toured the Netherlands) and the Rolling Stones.

While several Dutch pop groups of the era, including Tee-Set ("Ma Belle Amie"), Shocking Blue ("Venus"), and the George Baker Selection ("Little Green Bag"), all had hits in the United States on the Colossus label (resulting in what some music pundits jokingly called the "Dutch Invasion"), the Outsiders were unable to join in on this success as their records were never released in the country.

Later Outsiders singles had lower chart peaks, and personnel changes, friction, poor promotion and management problems followed.

The group began attempting publicity stunts in the hopes of building interest, including dressing in medieval costumes and staging a haircut for Wally Tax on Dutch television.