This is true for everyone who curates.
Personally in the case that I think a post I wrote needs more exposure I will promote that post @null. A few months ago I wouldn't consider self promotion but here it helps everyone if when I really work at something that I can make it known to curators.
@ajanaku, mineopoly has a great point and it's something I don't normally discuss. I will always save a portion of my liquid for post promotions on Ecency, PeakD, Hive, and POB or whatever tribe account I use. I can tell you from my perspective that use of the promotion feature works.