Hi, I just helped someone else with this so I will post my reply to him. Hope it helps you.
"I suggest you only do GMBs with addresses. Because of the proximity filter and the fact that almost all searches are done on smartphones now, service-based businesses are not given the same weight in my opinion as an actual location that Google can find using proximity.
The answer? Use a local address even if you have to pay for it, (executive virtual suite, friend, craigslist, etc) until they text you the card number and then you can stop paying. You can find any location for these services online. Try to find something central or the most desired area for whatever type of business. If you like the result, for major cities you can get multiple GMBs about 10 miles apart. As an example of this strategy, 1-800 dentist creates 100,000+ leads for their members from map packs for their members in each city using fake listings called "emergency dentist 24/7". If you want to see a sample, just set your browser to NY city and search emergency dentist 24/7 is the top 3. Try any major city and you will see they do the same thing.
So, if you are within 65 miles of the GMB service listing you sent me, just find a local address and you will not be required to get a new postcard. If you are outside of that, get an address mentioned above and then resend the card and ask them to text or send you the card as soon as it comes in. Anyway, you can replicate this anywhere there are GMBs."
