I don't see the point of "building readership" on free books unless you have other books to sell. Unless you just want readers, then that's cool. But it's certainly not a way to work toward a career. And, now more than ever, you can set realistic goals to have a career without getting the NY lottery ticket punched.
I'm publishing with a collective of skilled writers and I have the highest standards for my work, formatting, and presentation (and I have published six novels in NY so I know what those are). The successful indies will aim higher and for better quality than mainstream publishers, no matter their reason for going indie. And I can tell you it's not always because they got rejected by agents. I know several writers who never set out with that goal--they set out to build their own audience, own all their rights, and directly benefit from the fruits of their labor instead of giving up control of their work and receive 8 to 15 percent in return. They know what they are worth. That's a goal I'm working toward...starting to gather some evidence to make some comparisons. While I respect anyone equating $1.99 or $2.99 with "subpar," those are the prices that many indie writers find are fair in order to get a shot. And, those authors are making more per copy than many "big league" writers.
Scott Nicholson
The Skull Ring