Family and friends and the Amazon bestseller rank

I know Amazon flags reviews from family and close friends, but what about book purchases? If a pile of family members order my book on its first day of release, will I get in trouble? Will their purchases impact my bestseller rank either adversely or positively?

My short story will be in a very small category (History-ancient history-prehistory), and my family is large. I have 12 siblings and many aunts, uncles and distant relations.