There's a lot of talk bashing places that do "internet mastering". Understandably, you don't want to finely craft your songs and then send them off to someone who supposedly knows about putting the final polish on only to have them squash them all to hell with a couple "mastering" plugins and send them right back, possibly without even listening to them. There's a bright side though.
In the last year I've gotten drawn in to the group of engineers, both live and studio, that hang out on Reddit. In the course of that year we've seen many appeals for help with a project that was more than just a plea for advice. Some people showed up looking for people to collaborate with as an alternative to expensive studio time. Periodically there are guys that offer their services and while that's somewhat frowned upon, there are places to do that and people are finding work that way.
Of course every time this happens people come out of the wood work looking to work on a project just for the experience. That's a good thing really. The days of paying your dues at a real studio are fast slipping away and you've got to seek out experience where you can. More often than not the projects turn out OK. Someone with little or even no budget can get that last little bit of help mastering a project and the budding engineer walks away that much more experienced and with one more credit on their resume.
My own experience with this kind of work has been great. I've got friends who run studios right in the area who would love to keep their mastering work local. But I'm not up to snuff yet. Having some projects with less on the line to work on has been a godsend. The first couple I did for nothing, just to help some guys out and gain that little bit of experience. After a while offers for small paying jobs started coming in. And now after just a few short months I'm getting work pretty regularly. Nothing that's going to let me quit my day job (not that I would, I have the best day job in the world) but an extra couple hundred a few times a month for work I can do with my laptop has been wonderful.
It's been a real adjustment getting used to the pace of things though. The initial negotiations are always a little weird. Two people who will never meet in real life have to get to a point where they trust each other. One to put his or her music into a stranger's hands and the other to feel comfortable that they're going to get paid at the end. Luckily I'm used to putting musicians at ease, and the more my portfolio grows the easier that part gets.
The real stretch though is getting through that period of getting used to each others work and finding out exactly what the expectations are. It's no longer a matter of the client sitting in a session. That client might not even be on the same continent. So what could once be accomplished in half an hour of steady work at the desk is now a matter of sending version after version through DropBox until you finally hit gold. That stretches that first hour or so of work out over the course of multiple weeks sometimes.
It's worth getting used to though. In an age where anyone with a computer and a few dollars can set up shop things are getting ever more competitive. As schools continue to churn out "engineers" into an already saturated market the competition is growing ever more fierce. Learning to work in this new paradigm where the client and the engineer are at opposite ends of a broadband connection is a significant hurdle, but it's the way things are now and it's well worth doing.