Editor's note: This post has been updated since first published.

With its recently announced Starbucks partnership, mobile payments start-up Square is aiming to position itself, well, squarely in front of an increasingly long list of competitors. And it may just work: Square can't help but enjoy a higher profile now that it will be processing debit and credit card transactions at 7,000 of the coffee chain's stores. 

But the race to determine which tech company will dominate the mobile payment industry is hardly over. Forrester Research predicts mobile payments are still three to five years away from becoming mainstream.

In the meantime, here's a rundown of the key mobile payment players vying to get your business, and how their systems stack up.

Square

Square's products cater to everyone from the solo, mobile entrepreneur to high-volume stores, as the Starbucks deal shows. A free card reader lets you accept payments on a mobile device. Brick-and-mortar shops can plug the card reader into an iPad and use Square's Register app for a set-up that's more akin to a traditional cash register. Coolest feature: If a customer downloads the Pay With Square app, Register will recognize her when she walks in the store. When it's time to pay, she simply tells you her name and the system charges her credit card on file.

Pros: Register is easy to set up (it's a software download) and it offers back-end analytics and customizable loyalty programs. Plus, Pay With Square lets your cashiers see who's a repeat customer, how often they visit, and what they've purchased in the past, a feature that could help personalize your customer service.

Cons: Pay with Square only works with Square Register if your customer has downloaded the application.

Hardware: You'll need an iPad to use Register; the card reader works with iOS and Android devices.

Price: There are no monthly fees or contracts. Register is a free app. Square charges a 2.75% card swipe fee, a slightly higher rate than some competitors. As of August 16, Square offers a flat monthly fee of $275 and no additional swipe charges.

NCR Silver

This point-of-sale software platform that connects to iPhones and iPads is the priciest of the bunch. But if your business has multiple locations and a large saleforce, NCR Silver might be worth trying because it's cloud-based: The analytics can show you real-time sales data across all of your stores.

Pros: Along with the robust analytics, you get targeted marketing tools, such as the ability to send out daily deal emails to customers.

Cons: Merchants must have a Wi-Fi connection to enable the cloud-based system.

Hardware: Only available for iOS devices. A hardware bundle that includes the card reader, cash drawer, and receipt printer is $699. The optional barcode scanner sells for $499.

Price: A monthly subscription costs $79, plus the cost of equipment. To add more devices, you'll pay an additional $.10 per transaction.

GoPago

GoPago is one of the newest players in the mobile payment industry. As such, it's hoping to get ahead of competitors by giving its whole system--including a tablet, credit card reader, receipt printer, etc.--away to merchants for free. GoPago was designed with restaurants in mind: Customers can use the smartphone app to place and pay for orders without standing in line. The merchant software manages the orders and sales data.

Pros: GoPago provides 24/7 merchant support as well as analytics. The company says the system comes "ready to use."

Cons: On top of the swipe fee, you'll pay a 5% transaction fee if customers order ahead using the GoPago app.

Hardware: In partnership with Verizon, the JP Morgan Chase-backed start-up (the bank, incidentally, also backs Square) gives merchants a free Android Tablet with Verizon 4G connectivity. The tablet stand, cash drawer, receipt printer, and credit card reader are also free.

Price: GoPago’s transaction fee is a bit higher at 2.85% per card swipe.

PayPal Here

Already have customers using PayPal to make purchases? Then PayPal Here might be the best mobile payment option for you.

Pros: Like competitors, PayPal Here can process credit card transactions, but it also can accept checks and payments from PayPal accounts. The system supports cash tracking and easy inventory set-up. PayPal also provides a merchant discount when your customers pay with a PayPal card or a PayPal account.

Cons: Because PayPal Here is not a complete register application, don't expect robust analytics. Also, payments go directly into your PayPal account, rather than into your bank account, which may be inconvenient for some businesses.

Hardware: The card reader is free and works with Android and iOS devices.

Price: Card swipes have a 2.7% fee.

Intuit GoPayment

Intuit GoPayment is another plug-in card reader from a brand that is probably already familiar to many small businesses. If you rely heavily on Intuit's QuickBooks to manage your business's accounts, this one is worth a look.

Pros: Integration with QuickBooks is a feature that sets Intuit's system apart. The service also allows merchants to add up to 50 employees to the account, run reports, and void transactions on the spot (with other systems, you need to call customer service to cancel a charge).

Cons: There is no customer-facing app to pair with the service, so unlike many other mobile payment services, you won't be able to collect data on your customers and their spending habits.

Hardware: The card reader works with iOS and Android devices.

Price: You can pay per transaction at a 2.7% swipe fee, or pay a monthly fee of $12.95 and to get the lower 1.7% swipe fee.

LevelUp

Don't want to deal with swipe fees? LevelUp might be the best option for you. It's a cardless (and cashless) mobile payment system that stores customers' credit card numbers, so there are no processing fees. Customers simply pay with their phones. That doesn't mean it's free to use, of course: With LevelUp you pay for its customer acquisition and loyalty programs. 

Pros: In addition to the loyalty and acquisition features, you get analytics and inventory tracking. Customers get an encrypted barcode upon purchase, which they then present to the merchant. LevelUp can also be used in tandem with other payment services.

Cons: LevelUp is only accepting a limited number of businesses in the food service industry currently. Also, contactless transactions are still relatively new, so you may not have a broad enough customer base willing to use the system.

Hardware: LevelUp works on iOS and Android devices.

Price: The application is free. You'll pay for $.40 for every dollar of credit your customers use through the loyalty and acquisition programs. So, for example, if you offer a customer $2 in store credit and he spends $10, you'll pay LevelUp $.80.