Hi Quentin, I guess I wasn't thinking of you when I wrote that, because I already knew you're one of the few people on this board that isn't against it, and that you wrote a book on it.
Leonardo, in general, Microstock is basically Royalty Free images that can be sold anywhere from .25 cents (people like to say "you're selling your images for pennies!") to something like $40, depending on the size of the image, whether it's an extended license or not, and the PRICE MODEL of the particular agency (there's a lot of microstock agencies out there, some pay more than others).
(Some) People have a problem with selling their images at such low prices, but the key to success in microstock is the size of your portfolio, and volume of sales. Instead of making a few big sales a month, you make hundreds, or thousands of sales per month to be successful, and it's not too hard to do.
Macrostock is the more traditional places, like Alamy, that sells both Royalty Free and Rights Managed. Royalty free images from Alamy cost more than Royalty free from a Microstock agency. In order to compete with Microstock, Alamy just started this new thing called "Limited Use for $1." They had to do this to compete with their loss of sales from the Microstock agencies.
Rights Managed images from Alamy allows you to sell an image with a price that is determined by the usage. For example, the price of my Rights Managed sales (Traditional Licenses) at Alamy was determined by the size, media type, print run, etc.
Here's the details for one of my Alamy RM sales:
Country: United States
Usage: Editorial
Media: Consumer Magazine
Industry: Retail books/magazines/newspapers
Sub-Industry: Food and Drink
Print run: up to 1 million
Placement: Inside
Image Size: Spot size
Start: 01 December 2006
End: 01 January 2007
It was sold for $225. That's for one sale. That doesn't happen in Microstock with one sale. So it makes you think immediately that traditional RM and Alamy is the right path to go with because you can potentially make that $1,500 sale if you get lucky, but it might not be the right path. I'm one of the people who have moved completely to Microstock, making less per sale, but a very high volume of sales per month and per year in comparison to a traditional license agency. That means more money in my case. It might be different for you.
BTW, you can do Rights Managed and Royalty Free at the same time (Alamy and a Microstock site) as long as the images are not the same on both sites. Even if you've signed to be "exclusive" with a Microstock agency, you can still do Rights Managed at Alamy. Just don't do any Royalty Free at Alamy if you're with a Microstock agency. It's kind of against the rules. So try both with two sets of images. If one site performs better than the other, delete the images from one site (takes 6 months at Alamy) and put all your eggs with the site that is more successful.
If you don't do Alamy at all, you can also do more than one Microstock site at the same time with the SAME images if you don't go "exclusive" with one of them. For example, you can have a portfolio with the same images at 6 different Micro agencies earning from all 6 at the same time (it's tough to manage 6 sites, but some people do it).
One quick fact: 55% of all stock sold in North America is sold by iStockPhoto, a Microstock Agency, not a traditional agency.