I emailed some people a while back about pamfletoj (thanks to lernu's vortaro), and all of them changed the word to faldfolioj in their responses. What is the difference between the two?
PIV defines pamfleto as Verketo, en kiu oni akre atakas iun aŭ ion - J.C. Wells' dictionary defines it in English as "lampoon". It is a false friend, meaning that it sounds like the English word but means something different. (However, according to Google Translate "pamphlet" means "lampoon" in French, which is probably where the Esperanto word came from.)
J.C. Wells' dictionary says "pamphlet" translates to broŝuro, which PIV defines as Presaĵo, ĝenerale ne dika, kies kajeroj estas kunkudritaj k ne binditaj. Broŝuro occurs 100+ times in Tekstaro.com, while faldfolio appears only 16 times. This tells me that broŝuro is at least more common if not preferred.
Note that, according to a quick Google search, the English words "pamphlet" and "brochure" are used mostly interchangeably though there is a slight technical difference in how they are folded (or something?). J.C. Wells defines "brochure" as broŝur(et)o or prospekto.