Online shopping is growing by an average of 20 million new shoppers each year. That's a lot of people clicking and buying! You may be one of them.

However, there's a cost to online shopping that's all too easy to overlook. Shipping fees. Imagine saving $10 on a luxury cookware set, only to be hit with a $15 delivery charge. Ouch.

So how do you avoid those fees?

First of all, always check the fine print on the checkout screen. Notice what the shipping cost (if any) will be before you click the final purchase button. Keep in mind that the base shipping fee shown may update — and become higher — once you've typed in your address.

Some e-tailers offer free delivery for orders over a certain threshold amount; for example, $50. If there's more you can add to an order to get the shipping fee waived, it may be worth it.

There are a few e-tailers, most notably Amazon, that offer yearly memberships where one of the benefits is free delivery on all orders. Those kinds of memberships may be worth checking out if you do a lot of online shopping with a particular company.

A final tip: Always check for multiple delivery options. Some e-tailers, list an express shipping charge as the default option on the check-out screen, but have a free standard delivery option if you choose it.

Takeaway: Shipping fees take the fun out of online shopping. Do what you can to reduce or eliminate them!