Shopify gets our nod as the best POS for e-commerce and online retailers. The cloud-based system works well for small- to mid-size businesses, although the company offers Shopify Plus for customers doing over a million dollars' worth of sales annually.  On the company's website, Shopify touts that this is the product that works for you whether you "sell online, on social media, in a store, or out of the trunk of your car," and that seems pretty accurate.

There are multiple levels of service, starting with Shopify Lite at $9 a month. There's no online store included in this package, which can work for businesses who just want to sell goods on sites like Facebook, Pinterest, on Amazon, in person, or through an existing company website. You'll get a quality display that includes the highly-desired "buy" buttons on social media, the ability to create custom orders and invoices, along with the same 24/7 service offered to the higher package customers.

If you want Shopify to build your e-commerce platform from the ground up, choose from three options, starting with the Shopify Basic package at $29 per month, the mid-range Shopify for $79 per month, and Advanced Shopify for $299 per month. Your per-transaction fees are waived if you use Shopify's payment gateway, but even if you choose external payment gateways, Shopify's per-transaction charge is a fairly modest 2 percent for Basic, 1 percent for Shopify and 0.5 percent for Advanced.

Need a mobile POS for your brick-and-mortar store or hardware to accept cash and credit cards and print receipts? Upgrade to Shopify Retail for an additional $49 per month for all three plans.

Customer service is rated fairly well with Shopify, thanks to the site's detailed FAQ section on the website, user forums, and available 24-hour chat and email with Spotify support. There are nice added tools, like a logo maker and a QR code generator that will help your small business look a little more polished. The profit margin calculator may help you price your merch so that you don't lose your shirt. Another feature we liked from Shopify: Try it free for two weeks, without providing your credit card number.

See all of our  Best POS System solutions.

Things to Consider

As with any product that uses the cloud, you'll need a robust internet connection or a backup plan (which might include a hard-wired solution or using a hotspot off an existing device like your cell phone). In addition, there are some concerns about what happens when retailers leave Shopify for another POS system -- it's possible that your website may need to be completely rebuilt if Shopify's done all the work for you.