I've been making music for roughly 28 years and have been self-promoting it pretty much exclusively the whole time, with the exception of Hear Diagonally Records and Lujo Records which helped put out a few of my CDs. Footnote: a CD is a physical disc, like a frisbie with a hole in it, that spins around really fucking fast, and spits out a bunch of numbers at an insanely high rate. I've never been particularly good at music business or self-promoting; making calls, writing bios, engaging with fans, etc. But thanks to the internet, I can now do a lot of this stuff on a comprooter (sp?).
Thank you You Tube for having so many great tutorials online! Learn how to change a tire or fix your home plumbing in 5 minutes! And as you can imagine, there are a ton of tools for independent musicians to learn from. I've been watching videos by Jeff Price who had a hand in starting Tunecore, eMusic, and used to run a label called Spin Art. Really informative videos about how musicians are missing out on micro-payments by all the tech and media companies who are getting rich creating music platforms and tech gadgets.
Being a small fish in a big pond, sometimes it feels like YOU don't matter. If my music is not streaming in the millions, maybe it's not a big deal that I'm not getting mechanical royalties from You Tube and Apple Music. Maybe it's not a big deal that I didn't receive a Notice of Intent from Spotify when my music became commercially streamable. But when you know that these companies and their CEOs are making billions of dollars by essentially leeching off the cool of creative people, it does make it important.
Music has value. To humanity. Does it not? Since the dawn of time, people have been expressing their deepest sorrows and greatest joys through music. How can Amazon justify selling a brand new Lady Gaga album for $0.99! If one of the biggest superstars on the planet has her 12 songs sold for a total of $0.99 cents then all the little bands and artists are screwed, right?! Amazon doesn't care. They're hoping that you go to their site, buy the $0.99 album, plus some other shit they have on there and cough up $50.00 before you log off.
Why is a smart phone cool? It's cool because you can watch movies on it and listen to music on it! And play games on it! You can share any of the stuff you find and get other people interested in the great stuff you like. All of these people, like you and me, making this content allows these companies to market their items the way they do. Every stinking cell phone commercial has a hipster song in it. Every barf-inducing billboard has a picture of a skater or BMXer on it. Do any of the marketers or business-people have any of the cool cache their globbing onto? They need artists, so they should be compensating artists.
I realized recently, that even if the payout I would receive for all the royalties due to the copyright ownership of my songs was under $5, it would be worth it to me. It would feel like a win for all of the friends I've had through the years. Those who've put their blood, sweat, and tears into making music. So I filled out the forms. I went through the drudgery of writing down all my ISRC codes to identify my digital music. I made sure my copyrights were up to date and accurate. It was time consuming, but it felt good.

Sitting in with the Chuck E. Cheese band. They can wail!