ASL or Amelsan is the 3rd or 4th most used language in the U.S.; sign language has been naturally developed by fluent/native Deaf/Signers over the past centuries.

Sign language is natural, rich 4-dimensional (visual-temporal-spatial) language. People find it beautiful, unique, graceful and/or expressive.

Being a bilingual or multilingual expands your cognitive processes and literacy.

Some trivial or everyday benefits are: you can sign with your mouth full or talk through windows of a building from a distance. You can also talk lively in ASL in loud discos or whisper in a church or a library. You can be sure that nobody can overhear you through a door unless your door has a old-styled keyhole.

And a lot more.

Infants can manually talk their needs long before they can first vocally talk. Sign language boosts lingual and intellectual developments at the earliest possible.

A parent or a teacher can vocally speak a word and the child fingerspells out a word in spelling lessons.

Foreigners and travelers can cross a barrier of language, using manual/vocal gesture for learners and/or International Sign for fluent signers.

Sign language with its rich capabilities of cinematic vocabulary, rhymes and others adds a dynamic spice to visual-spatial language arts, storytelling, poetry and performing arts.

Human interest in communicating with animals (and perhaps vice versa) has been around for a long time, via speaking, signing and/or painting.

Entertain your guests with animals' intelligence and comprehension of a language.;)

Sign language is also an efficient communication for professional civic servants, such as firefigthers, police officers, scuba divers and other professionals (e.g. stock traders).