When you get some junk mail about credit cards or some shit, take the opportunity to use their free post return envelope to mail them some examples of your poetry (Anonymously and Do NOT Return Any Forms, of course! ).
Since they have to pay for the return postage they have effectively paid for your poetry!
And you never know, it might brighten up the day of some poor office worker opening the post.
FIGHT JUNK MAIL WITH POETRY & LOVE!
(…by the way, is it Guerrilla or Guerilla? I can’t find a definitive answer!)