A good friend has just sold a debut story to an excellent but non-paying market. There are a lot of markets for short fiction. Many of them are bad. Some of them pay. Some of the ones that pay the most are the worst. In the world of short fiction money is a very bad way of assessing quality.
There is a popular myth that back in the good old days writers could make a living from short fiction. It’s a myth continued in the idea of the ‘pro-rate’ of pay for short fiction. 5 cents a word can add up to a nice little bonus payment, but it’s only professional money if you are living in the 1920s. And only then if you lived on beans and fresh air. The only reason the ‘pro-rate’ matters at all is because it gives at least some indication that the publisher is committed enough to invest a little cash in their enterprise.
The only real measure of a short fiction market is the quality of its curation. As readers we rely on editors to curate the best material to suit our interests. That is why the average start-up fiction magazine that publishes thirty stories lacks any value, while the excellent Clarkesworld which publishes just two stories a month has become the top market in short SF. As writers, publication in an excellently curated market is one of the best indications that you work has achieved quality.
Writing fiction is not a manufacturing process. Success is not a product of your Rate of Productivity x Stories Published x Cents per Word. A dozen stories in a dozen ‘pro-rate’ markets can mean less than one story, in one well curated market which puts it in front of the right eye-balls.