Most people who are considering whether or not to upload to microstock sites are curious how much money can be made by doing so. (There are other reasons, too, but this is a biggie). The short answer is that it depends on how much time and energy you put into it, and it depends on the quality of your images. The top earners can make hundreds of dollars per day, but most people will not achieve that. For an overview of my experience, see below. I update the stats about once every month or two so you can get a sense of what I have earned -- without devoting a ton of time to it, to be honest.

I've written a short introductory article for eHow entitled "How to Make Money With Your Digital Camera (Selling Microstock)" -- take a look here. It is a short overview and I'm interested in any feedback you may have -- either to improve this article or for ideas for future articles you may be interested in.

Excerpt:

MacWorld has seven tips for would-be microstockers (see below). It's always helpful to read other people's summaries of the things that they find important. This is a decent list of basics.

1. Understand how it works: "...Selling stock photos is not easy money. It will take time to build up a decent sized portfolio (at least 100 pictures) before you see any sizable return..."
2. Think like a designer: "...Designers want photographs with ample amounts of uncluttered negative space so make sure you leave room for a headline or other text..." [Click the title above for more]

Here are a number of news items about Shutterstock's recent acquisition of BigStockPhoto. Each has an excerpt and a link to the full article.

Photo District News: Microstock Site Shutterstock Acquires BigStockPhoto

It's interesting to look back on the microstock experiment I started a few years ago. I have been quite lazy this past year about uploading anything--and expected my sales to dry up because of it.

If you're an artist, create vectors--they sell well and if they are sufficiently detailed, some microstock sites will tag them as more expensive downloads--meaning more money to you. Selling vector images at Shutterstock means working within the (essentially) all-you-can-eat package--which can also mean many, many downloads.

A number of microstock sites offer free downloads as a way to give you a taste of the types of images and image quality they offer. It's not a bad idea for designers on a budget to peruse these offerings now and then. Most notably, Dreamstime has a rotating selection of seven images available for free download at any time. Log in to the main page and look for the "More Free Photos" link to see all seven.

Make sure to look into referral programs on the various sites. Many of them will offer rewards for users that you refer to the site either as photographers or stock image purchasers. You can send your referral link to interested people by email or include the link on your personal website. Shutterstock and Dreamstime are particularly good for rewarding successful referrals.

If you want a constant (and constantly growing) revenue stream from microstock--upload new images regularly. Many of the sites sort images in a number of views from newest to oldest by default, so that designers who are regulars can find the fresh photos and vector images quickly. This means that the more new images you keep in front of them, the more likely sales will be. As well, the more images  that you have in your library, the more statistically  likely they are to show up in keyword searches.

Microstock, like most things, disproves the old saying, "Build a better mousetrap and the world will beat a path to your door." (Ralph Waldo Emerson?). If you want to make a sale, you need to get the image in front of people's eyeballs, and to do that, you need to find as many relevant keywords as possible. The more searches that hit your keywords, the more that your image comes up in front of designers. (Note that it is important not to "spamdex" your image in an attempt to get your image viewed using keywords that don't match the picture.