Technically anything that is done in effort to impact search rankings is considered "blackhat" in the "eyes" of Google. According to search engines you are only supposed to post content and let nature take its course. The real truth of this is that big brands are favored by Google and it's a classic case of favoritism where the little guy is left behind. Thankfully, with methods like PBNs it is possible to actually compete and even outrank these big competitors.