I recently read an answer to a question here that talked about holding certain investments to reap perks for shareholders (I don't recall the question offhand).
I'm interested in finding out more about what sorts of perks might be available from various companies, especially airlines, but I'm unsure where to look for information about the perks themselves and conditions for enjoying them (like number of shares, held for how long, etc.).
I'm not a very sophisticated investor, so I apologize if this sort of thing is concisely listed in routine investment information from companies.
What sources of information exist that can provide information about non-dividend benefits of owning shares in specific companies?