If it feels like you are getting more robocalls these days, it's because you are. Last year, some 30 billion spam calls were made in the U.S. This year, that number is expected to climb by more than 10 billion.

Alex Quilici runs the robocall blocking company YouMail.com, and said the most alarming part is the number of spam calls that are actually scams. Of the 4 billion robocalls made in August, nearly 1.8 billion of them were fraudulent. Next year, analysis by First Orion predicts half of all mobile calls will be scams.

Quilici's company makes an app that tells robocallers your number is out of order, tricking them into leaving you alone. But he said technology also enables robocallers to be ever more efficient.

"It's so easy to go make an enormous number of robocalls to people," he said. "If I'm a scammer, I can go annoy Seattle for 500 bucks."

If you send out enough lines, someone will bite.

"You get a call where it says, 'It's the IRS, you gotta pay us today or we're going to go to your work tomorrow or arrest you in front of your kids,'" Quilici said. "If you think you might owe money, it's a really compelling scam."

The number one way to deal with robocalls is never answer the phone with a number you don't recognize. But that's getting tougher to do, since scammers now use programs that make calls with familiar numbers, or even with your own number.