It's very common - you can use it any time someone thanks you. If you want something friendlier (Caveat! Remember who you are talking to, if you're thinking of using less-formal styles), then "no problem" works fine. In Australia we commonly use "no worries".

"You are welcome" can be used anytime you respond to someone saying some version of "Thank you", as well as related statements such as "I appreciate it" or any other such conveyance of gratitude. You can also use an adjective to enhance the response, such as "You are absolutely welcome", "You are most welcome", etc. This phrase can indeed be used frequently nowadays, for example, when at a job assisting customers either in person or on the phone, as well as outside work.

You are welcome, or You're welcome, is slightly formal, but still used.

"You are welcome" is pretty frequently used, however, most people would say "you're welcome." It is used as a response to "thank you."