Let's just get this pesky one out of the way because we all know we've used this excuse. I'm guilty of it too. What this translates as is, "I'm prioritizing other expenses over my music career. " Some of them may be legitimate expenses too, and some of them may not.
But if it comes down to having cable or putting more investment into my music career guess which one is going? (Sorry Walking Dead)
What I've come to find is there's always a separation factor for the more serious artists. A higher percentage of their funds are being attributed towards their craft because they are the few who sincerely want to do music full time.
Not every artists who says they want to actually does though. The investment is one way you can tell.
Not to mention how freaking cheap some smart investments for your music are.
Domain name ($1/month). Hosting (As low as $4/month), A GOOD Mailing list (Not ReverbNation) (As cheap as $10/month). That's not even $20... $20!!! (Sorry for yelling the second time) There's really no excuse for serious artists not to find a way to invest the $20 though, and a very small percentage actually go through with it.
However, if you don't know how to use these tools and properly structure a website it's useless to invest in them, so keep reading.