Hey Edward,
I wouldn't call it your ignorance, it's a very good question indeed.
Blogging outreach is one of the technique of content marketing. Imagine this scenario, after spending days you finally produce something very exceptional that no one has written about and you published it with full of excitement hoping to get the appreciation and shares. But, it's all wasted because no one knows about you and didn't notice your tweet.
Most of the time, you cannot be able to create that "ideal traction" either because your brand is new, your social following is low and no one noticed that you shared something mind-blowing or only your employees and friends are in your mailing list.
This is where the concept of "Outreaching" applies i.e. to get the list of people, influencers and bloggers to let them aware of your content by emailing them, pitching them on social media etc.
The whole purpose of this practice is to increase the reach of your content so that people started to recognise you.
Hope this helps!
Umar