I'm not a vector artist but I really like your stuff! As far as I can say your characters (snowman, people, animals) like well proportioned which is something a lot of illustrators are struggling with.

I can see your stuff selling really well at Zazzle and Cafepress plus you can set your own commission which makes it even more attractive.

Maybe microstock is not the best place for such illustrations.

Some Zazzlers can easily rake in a couple grand a month with wedding invitations, baby shower announcements etc. using just that style. Do a search on Zazzle to see the competition. It's hard to get started - BUT - there are no reviewers!!! You need to get a critical amount of designs in your store and ideally direct traffic to your store (Twitter, FB, personal referrals etc.). But even their own marketplace search engine can earn you several hundreds a month.

I didn't check a lot of your images in regards of keywords but they looked ok from what I saw.

I'd say keep doing what you're doing. Apply to more sites - it's tough but it'll pay off in the long run and think about offering print on demand products like Zazzle.

Best of luck!

One thing to consider is that perhaps your target market doesn't have the expertise to take the sample text off of your images. A lot of your images look like they would sell to new mothers and other non professional customers. Your sample text might actually be hurting your sales because the customer can't figure out how to get it off. If they have to download the vector file to remove the text they are going to be stuck if they can't open the file because they don't have the software. Your images are very nice but I think they are unusable to many of the people who would like to buy them.

Consider changing your approach. Stop being a designer and start being an illustrator. Think of your images as "parts" of someone else's design, rather than finished designs themselves.

Finally - I agree about Canstock. Other sites I like are Bigstock, GL, Yay, ToonVectors, Stock Fresh and Stockami

These sites tend to work better for Illustrators than Photographers. Some are new but their sales are growing for me.

I totally agree with my colleagues, your portfolio and images style are very cool!

You portfolio probably only needs more volume of the same quality images... maybe like say cthoman also working on a variety of themes
How long have you been on Shutterstock ? It's a bit long to wait for really better earnings, but if you keep working the same way, i don't doubt you will be earning more $, with lifetimes earnings growing etc.

Keep up the work and good luck !