I cringed, as I looked in my bank account. I had left Google ads running, and they had debited my account $500 after forgetting to turn them off. This was one mistake I'd never make again. 

This year marks the second anniversary of my Etsy and Shopify stores. Along the road to profitability, I've made a handful of mistakes. Here's three of the most common new sellers tend to make when getting started with online selling.

1. Not doing the research.

When I first started my store, I was thrilled when I got my first sale. It was validating to see my ideas might be good, and I became over excited at the prospect of selling more. I quickly created hundreds of new products without doing any market research. In my store, I made hundreds of products that I thought were funny or that I would want as a consumer. Two years later, I've learned that by researching keywords and getting market feedback, I'm able to make products that have much more market demand. 

When you're thinking about creating a new product, check to see how many people are searching for similar products and how much competition is currently in the marketplace. You'll save yourself a lot of time and money on items that may be a flop.

2. Not spending enough time on marketing.

I'm guilty of this. I love creating and if I could, I'd spend all day sitting at home making new products. What I should have done with my store was create less products and spent more time promoting each one. 

This year, I'm stopping my creative wheels for a while, and focusing harder on promoting the existing items that I have. When you're working on your online store, know that the hard work doesn't stop after you release a new item. You'll need to spend weeks to months promoting them to ensure their success.

3. Build a community of support from other sellers.

When I first began selling online, I knew very few people who were also running their own stores online. The first months were hard when I would run into a stumbling block. Since then, I've found great seller groups online on Facebook including "Etsy Sellers Only" and "Getting Started With Print On Demand" and have made great connections and friendships. When you're first getting started, find others who are selling online and ask them to take a peek at your store. They'll quickly be able to see any astounding red flags that might be hurting your business.

Today there are so many tools available that you can have your own online store up and running in a matter of hours. By avoiding these three beginner mistakes you'll be well ahead of the competition.