Music will always be around until it is banned by governments
Self promotion requires you to actually do it. its the only way. you can't half ass it. if you're putting yourself out there do it properly. craft yourself for your audience and what you want to be. a dubstep DJ/producer is far different than an electro-pop/pop act or whatever.
develop a brand, this might take a while. a brand is not posting sick memery on your facebook or sharing UNILAD videos/Worldstar videos to get hits - that just shows you spend more time on the net instead of probably making meaningful music.
you can do your own art but if you're shit at it i'd say pay someone to do it. could be the start of a good collaborative process. if anything find a new comer artist and work a deal to help each other promote one another, you can probably get work done for free.
oh yeah, you're gonna do a lot of that; paying for it yourself - especially as a budding artist, its just how it is, special circumstances can apply but youll need to spend some $ on your brand/self/promotion
contact like minded blogs/places on the net that support your type of music
if you're producing country nobody cares about it on a pure trance forum, unless you're Avicii, yeah someone like that.
but first you have to make good, meaningful music. its a real bummer when the branding is great, the artwork is tight and everything works except the music. focus on that first.
people relate and gravitate to real, raw art. despite it being 'gay' or lame or too deep or slow or whatever in some circles of society, make good art. you have to or else nothing will work. might take you a week might take you 7 years or 10 years but make good art.
promotion is small peanuts imo and its just about manipulation of your audience, thinking in their shoes and providing a product they'll want to consume and be apart of.
self promotion has been around forever and is not new in the music industry. independent artists have been around forever as well as indie labels and the like.
the music should be able to promote itself by virtue of being unique, meaningful to the listener, etc.
you could say in some cases luck does have a factor, right place right time.
networking is your friend, it really is. talk to people, reach out. don't be annoying but be proactive about it. you literally do not know who is looking for work/hiring/needing to fill their roster.
these are my opinions from observations of the industry itself, which i work in (more game sound design), friends, other producers and watching the up's and downs of the industry itself as an outside consumer.
but it still comes back to your effort. you can wait around for prince charming, he might come or you can go find whatever it is you're looking for yourself.
good luck! don't forget to post your album here so people can listen--- you can also search the forum for 'Promotion' or other things pertaining to this question as I have seen some good advice from people, like using email chains on Bandcamp (i think this was a @chasedobson
technique, or Benwaa I forget) and various other theories and ideas on how to get yourself "out there"