Nothing like getting an unasked for guild invite when you're in the middle of a dungeon run... fighting the boss. Nothing like dieing because you're forced to either accept or reject an invite. Nothing like id10ts who think sending out blind invites to people they can't see to their guild, will get them anything but animosity. Nothing like having to click the "remove from searches", not to avoid gold seller whispers; but to avoid random guild invites from thoughtless fools.
1) If you can't physically see the person on your screen and they didn't ask to be invited into your guild do not send an invite!
2) If I didn't ask to be invited into your guild do not send me an invite, period.
I'm picky about what guilds I'll join and getting a blind, unasked for invite is a sure fire way to ensure your guild does not make my short list.