Writer Pay Options

In searching for contests and publications taking submissions, I come across a lot of different ways a writer can be paid (or not). The most common types are:

1. Per word payment
Author is paid per word in their piece, sometimes varying per length (as in, one rate for short stories, one rate for poetry, one rate for novellas). Duotrope breaks it down into token (<$ .01/word), semi-pro ($.01-.049/word), and pro (>$.05/word).

2. Flat payment
One flat monetary payment per piece, no matter how many words. This flat payment usually varies per overall story length (i.e. short, flash, poetry, novella, etc.), but doesn't take into count exact word count. Example would be $25 per short story.

3. Royalty-based payment
Typically, you are promised a % share for the amount that comes in for the sale of the book or magazine. Some do a tier system, while others offer all authors in the piece an equal share. This is after costs of publication are met, and means you will only be paid if a profit is turned.

4. Charity
With this option, you submit with the understanding that your piece will make you no money, and that all proceeds go to a charity that has been pre-selected. If no charity is selected, and it just says that it will go to charity, I recommend avoiding it.

5. No payment
This is often found with upstart magazines that are trying to gain a foothold in the market. They may promise exposure, free advertising, your name on their website, etc., but you will not receive money. Some may state that they will revisit lack of payment should they bring in enough money.

There are many other options and mish-mashes of the above (for instance, I recently found one that paid a small flat rate to start, followed by royalties should any be received). So far, my personal experience has been with a charity anthology, a per-word magazine, and flat-rate per article payments. I haven't submitted to anyone saying they pay by royalties yet.

I'm seeking opinions and experiences with the various types of pay. If you've worked for royalties, how has that gone? Do you prefer one of the above methods of payment? Which one, and why? What way(s) would you never consider submitting to?

May you find your Muse.