The publicizing of the salaries is only one of the many unusual things which Buffer has done. The benefits are that of transparency. Whether or not your company culture can support that is a different story.
I don't quite understand Buffer's logic of making everyone's salary (identifiable with their names) available to anyone outside the company. Scenarios as to why I think so:
Regardless if transparency of identifiable salaries is a good idea or not, it for sure doesn't seem like a good idea to show to anyone outside the company.