|Johanna Spyri, writer|
For about 50-70 years, they paid the same pennies-per-word rate as at the beginning, so by the end, it was the prestige and not the money which motivated. And the pulps have fallen out of favor as radio dramas and then television provided the major entertainment source for most people.
So, how does the neophyte writer serve an apprenticeship today? By writing for free. You are of course writing for free anyway on your initial short stories--- in the absolute beginning stage it's better to write many stories one after the other, rather than revising your first precious jewel endlessly in hopes of making it good enough to publish. But I'm talking about a different kind of 'writing for free'.
In the beginning, your writing-for-free will be centered around your blog. Since you are not ready for a full-fledged author blog until you have a few published novels under your belt, your blog theme should be about your chosen genres (if you've chosen one yet) and perhaps about writing--- in order to attract other neophyte writers, and perhaps more advanced ones looking to promote their books. (You might even share some of your writing on your blog.)
Your blog is a free sample of your writing. It gives potential readers the chance to evaluate whether you can write a correct English sentence without a net. (Or a correct French, German, Nepalese or Esperanto sentence if you are a native speaker of those languages and will thus be writing in them.) That's why it's so important to use correct spelling and grammar.
If you have started out writing fan fiction, another form of writing-for-free might be to post your fan-fic short stories on a website that specializes in this. I don't know of such a website, offhand, though I'm looking for one (I have a short story in the works where Captain Kirk and Doctor Who are kidnapped by a Really Bad Dude, possibly Lord Voldemort or Mr. Burns, and must be rescued by Idris and some Enterprise crew, and perhaps Romana.
There are other sites for original short stories. Both of these kind of sites, I'd imagine, are homes of the most amateurish writers imaginable, and they will give you insincere praise in order to get you to read and promote THEIR fiction. But it's a place to get your work looked at. And if it is original fiction, publishing it on a password-protected story-site such as these does not count as 'publication' and so you can, at a later date, sell the fiction to a paying publisher. (Publishing it on an open blog does count as publication. And password protecting your blog means you'll have virtually no readers.)
Another form of writing-for-free is to write a story or novel and make it available as a free ebook on Smashwords. (Note: be very clear to let the audience know if it is a short story or novel so they won't be resentful when it ends too soon.) Catholic author Amanda Borenstadt has two free short-short stories at Smashwords featuring characters from her novel Syzygy.
Even well established authors benefit from the writing-for-free thing. Baen books had the Baen Free Library, in which Baen authors were permitted to offer some of their older books as free ebooks. Often these were the first novels in a series--- which might encourage readers who liked the free first book to buy the next book in the series. Authors who have participated in the Baen Free Library include one of my all-time faves, Mercedes Lackey.
Mainstream publishers are also looking in to the idea of making a book temporarily free. I got a free copy of Jerry B. Jenkins' novel 'Riven' that way. I picked it up because it was free, and when I read it, I really enjoyed it. If I hadn't already been a fan of Jenkins from the Left Behind series (in spite of the theology mistakes), I would have been more likely to try other Jenkins books after reading this free-sample novel and finding out, yes, the man can write.
Warning: just because I've said writing for free is now part of a writer's life, don't be taken in by the vanity presses who want you to write for less than free--- they want you to pay to get your work published. Sometimes they will claim they publish for free--- but you are required to pay for services such as editing, marketing and the like. A vanity-press book looks very bad on your writer's resume--- you'll be best off never mentioning it to a real publisher. (A self-published book is also better off not mentioned unless it sells well.)