I agree! We've been using their service for around five years.
The way that Nomorobo works is that you set up your phone service to have incoming calls ring simultaneously to a Nomoboro 800 number. Nomoboro compares the caller ID information with a database, and if they recognize the number, they intercept the call after one ring, therby blocking robocallers. Live callers hear a recorded message that tells them how to bypass Nomorobo, and live telemarketers or scammers can use that bypass to confound the system. The system relies on that master list of known robocaller, so if a spam callers gets through, you can send Nomoboro an e-mail to ask them to add the caller ID information to their database.
In recent years, the robocalling 'industry' has adopted a new strategy of trying to fool you into believe that their call is coming from a neighbor. They do that by using a spoofed caller ID that matches your area code and exchange. There's no way that Nomorobo can catch those calls since they spoof a different caller ID number for every call.
But there are other things you can do. For example, I have our phone system to also simultaneously ring to my cell phone. The initial rationale for this was to make it possible to answer incoming calls without scrambling to get to the house phone. But then I realized that iOS has two features that can be used to provide additional call screening. One is to direct all incoming calls that are not listed in my contacts list directly to voice mail without ringing at all; I can answer directly any call from someone I know, but if I don't know the caller, then I can use voice mail to screen for fraudulent calls. The other feature is the ability to specify combinations of area codes and exchanges from which calls should be blocked. That takes care of 'phony neighbor' calls. My wife's Android phone as similar features.
Nomorobo is free on wired home phones, but your phone system must allow you to set up simultaneous ringing. That feature is usually available in VOIP systems (such as Spectrum, etc). It was not available on the traditional Verizon system we used to have (although that may have changed by now.) You can also get a Nomorobo app for your cell phone, but it is a paid subscription service. So I've opted to use a free screening app called HiYa that works in a similar fashion.
I keep a list of the bogus calls we receive on our home number. Since the beginning of this year, we have received 51 calls - there have been a few days when there have been no calls, but typically we get 3-4 per day (two calls so far today - and it's still morning!). Fortunately, with the combination of screening tools, I now only have to actually speak to the nice lady offering to help me avoid credit card interest about once a month.
