Perseus,

I don't think it avoids theft, but possibly RM buyers understand more the restrictions of a license.  Nothing impedes them from using the image outside the original license.  For instance, I sold an image to be used in 5,000 copies of a textbook.  If the publishing company prints instead 10,000, or use it in another textbook, I may never know to complain.  However, since it's a traditional publishing company, I don't expect them to do that.

The control RM allows is of the usage. A buyer may want exclusivity in a certain country, and I can only guarantee that with RM.  If I license an image this way, I can not license it for worldwide use to another buyer.

Also, I am very sensitive about images of children.  I have never sold any, but the ones I have I would only sell for a very specific use. For instance, I have images of refugees in Africa, I would only sell one if the buyer's usage is editorial for this specific theme (not child abuse or AIDS).

I'm interested to know if people have other opinions about RM.

I would also add that our main difficulty is when selling an image at micros, when they sell a lot, because we never know if a certain person is using a legal copy or one redistributed by an legal buyer (intentionally or by accident) or even resold in a CD by someone who bought a subscription. 

RM doesn't prevent theft or misuse. However, it can help with copyright violations.

Since no place else I license images uses the RM model anymore, I've marked my RM images on Alamy as exclusive. This got me a $250 copyright violation fee for an image of mine I found in a book that I wasn't paid for. Since the images was RM and exclusive to Alamy, Alamy chased up the use. It took nearly a year for them to collect and pay me (I finally got the payout in October of this year), and I brought the use to their attention. Still, even in this instance, it was the fact that it was exclusive to Alamy that made the difference. Moreover, the image had been credited to me and Alamy (which is how I found it) but with their loosey-goosey self-billing system, it never showed up on their end.

RM gives you more control over the use of images, letting you prohibit sensitive use, reproduction for fine art, etc. It also means that you are supposed to get paid a fee each time an image is used.

That control, however, can be elusive.

I have RM images on Alamy that they have licensed "in perpetuity," which might as well be RF. This is more and more common, and very frustrating.

A few years ago, Alamy licensed two images for a particular edition of a book under what appeared to be normal RM terms. Those two photos were reused in several subsequent editions of the book, without additional payment. When I notified them about this the first time, I was told that the license was worded to permit subsequent editions (despite the notation not appearing in the licensing info I received). Even at half the initial fee for subsequent editions, that's $$$$'s that neither Alamy nor I earned. Frustrating.

I have some photos that I often sell as fine art on Alamy as RM, with "do not sell for personal use" (i.e. one-off fine art prints) ticked as a restriction, so it doesn't undermine my prices. A couple of years ago, however, Alamy sold a series for $169 each, one was personal use for prints (an older scenic from the same area that I uploaded before Alamy changed the way we added RM restrictions). The other two images, "ticked as "not for personal use," were sold for newsletter use. I assume they were all printed but there was no way I could check on the license. I made less than I would have for a decent sized print, but at least it was a couple hundred to me, and not the measly $10 or so I'd get when they license RF images for print. Cynically, I assume they did it this way to make it worth enough to me that I wouldn't make a fuss.

My decision about when to make an image RM has evolved over time.

When I started in 2008, I used to agonize over which images should be which, which to upload to Alamy when all sales there were truly midstock or even macrostock prices, and this slowed me down in building my portfolio.

Then, I tried a few of my best travel images as RF on the micros and they made me way more $$$.

So, I think RM is worthwhile for certain images but most of my stock portfolio, even on Alamy, is RF. And my criteria for marking some as RM has evolved as well.

These days, I am selling more scenic fine art prints, so RM has become a way for me to license certain botanical images to magazines, calendars and books while still selling prints. I also do a lot of black and white more abstract images, which I don't upload as stock, and which I wouldn't license except for use in a fine art book or art show catalog. There, an RM license, even if it is gratis for a catalog, lets me protect the use of the image.

So, yes for me, RM makes sense. I got a few decent $$$ licenses this year, but I also had a couple of $$$ RF licenses. And just this month, I had RM images license  $7 and 16.  So I don't think that prices for RF and RM are necessarily all that different. In my experience, at least, it's much more about having some control over the image's use.

I do this part time, so I don't have a ton of data, but I hope the examples I've given you, some older (e.g. the book and subsequent editions) but mostly from 2021-2023, help you make a decision.