From Square to PayPal, there have never been more ways to part with your hard-earned cash—without actually handling said cash.

Like those other digital payment services, Venmo allows you to send or request money with a few quick taps and swipes of your device. But unlike other money transferring apps, Venmo (which is owned by PayPal) adds a dash of social media flair to its interface, says Erin Lowry, a personal finance guru and founder of Broke Millennial.

When you send or receive money using the app, a record of your transaction appears on your Venmo homepage—minus the amount of money involved—for you and other people to see. Like your Facebook homepage, you can configure Venmo to share your transaction record only with your friends, or with the general public, Lowry says.

You can also include a note about the transaction. For example, if you send your male roommate $40 to cover your portion of the electric bill, you might joke, “Powering John’s hairdryer and curlers.”

Consider it one more way to (over)share details of your life with other people. But while Lowry says she loves Venmo, there are right and wrong ways to use it.

Venmo is ideal for splitting dinner bills, paying friends back for stuff, or collecting money for a bachelor party, Lowry says. Basically, use it for transactions that involve close friends or family.

Nobody carries much cash these days. And even when they do, it’s awkward asking a buddy (for the third or fourth time) to pay you back that $50 he owes you for karaoke. Once you start using Venmo, you realize pretty quickly that it’s a lot less weird to buzz your buddy a “you owe me” reminder than it is to call him or ask for the money in person.

Especially if you have roommates, or are still young enough that spotting a buddy a twenty is a big deal, Venmo can quickly become indispensable.

Venmo is not so hot when you’re dealing with strangers—particularly when you’re selling something on Craigslist or similar platforms, Lowry says.

If you dig deep enough into Venmo’s site, they make a point of saying their app is not intended for exchanging payments for goods or services. “Some people have experienced fraud as a result of being a bit too trusting when selling products to strangers,” Lowry adds.

Here’s the really tricky part: When you get a notice from Venmo that funds have been transferred to your account, that’s NOT the same thing as having access to those funds, Lowry says.

It can take 24 hours or more for those funds to actually transfer, and that window of time allows scammers the chance to collect your goods, make it seem like you’ve been paid, but then reverse the payment so you don’t see a cent, she explains.

The Venmo app uses, in the company’s own words, “advanced security and data encryption” to keep your bank account information safe and sound. But those built-in security measures won’t do you much good if your phone itself isn’t protected.

Lowry recommends password locking both your phone and the Venmo app. “Double up the protection by ensuring your app’s pin passcode is different than the passcode to get into your phone,” she advises.

That way, a scorned ex who knows your pin can’t swipe your phone and levy what she calls an “asshole tax.”

Bottom line: Venmo simplifies buddy-to-buddy transactions, but it’s not a do-it-all payment app.