Sorry, but I don't think these have potential.

I don't know if they have potential, but I don't believe they are in high demand anyway.  Some may be used as backgrounds.  However, to be approved in any site you must show more variety. 

These seem almost like fractals, which I believe have a hard time getting approved by the major sites these days. 

But assuming they do get approved, think about the uphill battle they will face getting seen by potential buyers.  It's all about the keywords.  You'll probably be hard-pressed coming up with more than a dozen for each image (background, color (list the major ones), shape, abstract, geometric, etc.)  Now imagine how many images will come up in a search on those keywords.  I think it would be nearly impossible for a newcomer to find any success with this approach. 

But I don't like to discourage anyone, so here's some positive advice... instead of creating generic backgrounds that will fight against tens of thousands of other generic backgrounds that have already generated sales, try creating backgrounds around a specific theme, something that's niche and marketable.  Then you'll have deep and rich keywords that will get your images seen.  What do I mean by "creating backgrounds around a specific theme?"  I'm not even sure, but you'll need to do something different, something that addresses a specific need, if you want to generate sales.  I hope this helps.

I'm going with the minority here. I do think they have potential. To get your foot in the door, you do need to show a variety of styles. Theme-wise, think that is a good idea. Start with holiday type colors and cover the big ones, Christmas, hannnuka, Easter, valentines, red white blue etc.

Just my 2 cents. If you're going to start, I'd go with middle and low-tier first.

If you're going to take the time to try and get involved in the microstock business, I think your time is best spent creating some images that have the potential to fill a need in the market. And frankly, these fractals don't fill any sort of need. Even among established artists who create these types of images, I have yet to see any convincing evidence that fractals are a worthwhile endeavor in microstock at all.

Some people have entered this business in the last year or so and done well. No doubt it's harder to enter into this business now than it was a few years back, but it's still possible. But you had better bring something interesting if you're going to stand out and actually generate any decent amount of sales. And fractals are just about the most unoriginal thing you can bring to the table.

Alright, "fractals" aside (I do have 'themed' versions, btw), say I want to start in microstock but don't want to get into the 'photography' side of it yet, meaning I'd like to stick with 'illustrations' for the most part. Which site would be best to start out in? I'm looking at the mid-tier companies for now. Someplace I can learn.

Alright, "fractals" aside (I do have 'themed' versions, btw), say I want to start in microstock but don't want to get into the 'photography' side of it yet, meaning I'd like to stick with 'illustrations' for the most part. Which site would be best to start out in? I'm looking at the mid-tier companies for now. Someplace I can learn.

I don't quite understand why you would start out with a mid-tier company.  Start out with the best so you can be the best.  If you start out with the best sites you will be more encouraged by the sales you receive and get pickier reviews, pushing you to create better content.  Start with the top 3-4 sites.  Shutterstock, iStock, Dreamstime, and Fotolia

Dreamstime and Shutterstock imho