The «Other Carrier» category generally reflects those airlines that operate within specific niche markets such as Hawaiian Airlines serving the Hawaiian Islands. (transportation.gov)
This is aimed at a very specific niche market, and does not even have a built in e-reading software. (goodereader.com)
«Every day there are new sites out there that are focused on specific niche markets - it seems to be all the buzz.» (onlinepersonalswatch.com)