Who called from 4018681990

Someone calls multiple times per day, AM/PM, & never leaves a message.  Appears as "out of area".

So far we have received 6 calls from (401) 868-1990.  No message has yet been left on our answering machine.  
Thur 02.27.14    @ 2:48 pm
Fri    02.28.14  @ 6:34 pm
Sat   03.01.14    @ 11:58 am
Sat   03.01.14    @ 3:40 pm
Mon 03.03.14    @ 7:48 pm
Fri    03.07.14    @ 7:14 pm
The CID reads "Providence, RI",  and the White Pages says this number is a Voip from Rhode Island.

I've gotten 3 calls so far from this "person"...no message left

I known no one at 401 area code, no message leaved.

Marketing research, left message with call back number. Said they were recruiting music lovers, willing to pay 40 bucks for your time.