What is microstock photography?
Microstock photography is a subset of the stock photography industry and refers to royalty free images sold at very low prices (microstock photography is also called "micropayment photography"). Microstock companies source stock photos from a large volume of photographers, and are known for being very willing to accept submissions from amateur photographers.
Now that you know the generic definition, we can move on to the specifics freelance writers need to understand about this type of stock photography. Previously I've written about how to use professional stock photographs to help you successfully pitch and sell editors and clients. Notice the word "professional" in that sentence.
There are some professional photographers who go as far as saying the microstock business is devaluing the entire profession of photography. That is a bit dramatic, but just as successful freelance writers can quickly tell the difference between cheaply written content and quality copy from a professional the same is true for stock photography.
With the benefit of being able to get cheap stock photographs can come the tacky look of an unprofessional image. As a freelance writer it is important to remember that everything you turn in to an editor or client is a representation of you. If you provide an editor with superior content next to cheap, generic photographs your entire body of work has just become less impressive.
This is not meant to come across as a strike against all microstock photography. There are some quality microstock photos shot by very experienced photographers. This is just a heeding to make sure the quality of the stock photos you purchase match the high quality of your writing. Ideally you would be able to utilize high quality, professional (and affordable!) stock photos to improve the overall "package" you create for an editor or client.
The other thing to consider is the value of your time. Usually you're using a stock photograph to save you the time and expense of creating (or hiring a professional photographer to create) custom photographs to accompany your writing project. Due to the large amount of microstock photos usually on microstock websites, you can end up spending just as long (or longer) wading through hundreds of lesser photographs (more photo options can be both a positive and negative) before finding the professional, technical quality you feel confident showcasing next to your copy.