You can be as specific as you want, but if your search is too narrow you will end up with less than you want. For example, if you pick just “Leftie” for your political preference, and an advertiser said he/she was a “Democrat,” “Liberal,” and “Far Left” (but didn’t check “Leftie”), that person won’t show up in your search results. Moral: unless you really care about a single characteristic, either accept the “No Preference” default or pick all that might be acceptable to you.