1. Stock photos need to be useful to the buyer, not just pretty, or a function of the creator's artistic vision.

You'll need excellent technical quality for most stock (some agencies taking mobile shots may be more forgiving). You need to be aware of legal issues - intellectual property rights (can't use logos, copyrighted written or visual works, model releases, property releases) - for stock. You need to be able to keyword well - if your images can't be found, they won't sell. Learn how to light an image - or manage natural light; what works for family vacation shots won't do for stock. Think about how someone could use an image - magazine, web site, advertising - not whether you like the scenery or the model is gorgeous.

2. Be prepared to work at this and learn - don't assume that because you know how to take a good photograph that you're all set. If you don't have a thick skin and tolerance for rejection, you'll get frustrated and give up pretty quickly.

Stock is work.

You need to have a very high level of resilience to deal with the daily frustrations - rejections of your favorite images, lack of sales, glitches that make agencies unworkable, often in the most important buying season.

Lack of communication or simply being completly ignored and left out in the cold. People that copy your bestsellers, especially if the agency shows visible downloads, people who will steal your file and upload it as their own. Etc...

Then the lack of sales, it can take a few years until you understand which niche you will do well in or until your quality is good enough. Even professional photographers or art students are often frustrated with the strict quality demands.

The frustration that everybody around you uploads work that is so much better and yet...is often amazingly young. Especially for artists who have won prizes and have some local or national recognition, it can be very hard to accept that the big bad world has so many people with more talent and dedication than they do.

Competing in a globalized market where many stock artists benefit from living in countries with lower running costs for daily life and staff.

Most people I know give up on stock very quickly. Last year I worked with a talented guy who had set aside enough money for a year and wanted to produce 2000 images. i think he had 800 in the end and never made more then 50 dollars a month. He then got himself a dayjob in a different field and is back to doing either art or portrait assignments.

The daily discipline needed when you have no deadline and also it is very easy to get lost in details and lose track of time.

Especially if you do it all alone, it is very hard.

And it is so much easier to make money faster if you invest the same time into assignments. plus...your client gives you a deadline...

Photography is one of the most popular hobbies in the world, but to become a successful stock artist you need a lot more skills than just to be creative and make pretty pictures. Artistic talent is nothing rare, most people can do it, they just don't have the time to.

For stock you need the same kind of determination of a stubborn engineer who keeps going over his project again and again until he has what he wanted.

If you cannot challenge yourself to go beyond what makes you personally happy it is unlikely you will make serious money.

Art can exist for itself alone, doesn't have to please anyone and it doesn't matter if 1 cent or 100 million are virtually assigned to it as a financial value. Even art with no commercial value can be extremly important for the evolution of art itself, just like music.

But stock has to convince somebody to part with their hard earned cash and a stranger you will never meet uses it for something. Perhaps to print designer toilet paper...

If nobody ever buys it, stock has failed it's purpose.

It can still be (only) art, but stock has to be useful for others or it is simply not stock.