I use a mailbox and it works fine. My box # is 170, so for the address I just put the address of where the mailbox is located, and say "suite 170" and that's it.
It works perfectly for Google places
To all:
When I read this, I sent a PM to confirm that wally666 was truthful, as frequently we see "wild claims" that, unless they are verified, can 1) sometimes send people off into nonproductive directions trying to accomplish things that are doomed to failure, and 2) give undeserved "reputation" to someone that claims to be able to do something when they cannot.
Neither of these is happening here, as I have verified from the OP's PM that he has in fact used an address in his Google Places and G+ listings that is not strictly a place of business. I won't say exactly what the location IS (I'll leave that to him, if he wants, as it could be legitimately called a "method"), and I'm not going to out him on that, particularly after he trusted me and sent the GP listing for me to verify.
It's what it is not, which is what's important, because I very much doubt that Google would find this type of address acceptable. It's also possible that if they are "tipped", they could easily tweak the algorithm to exclude them, so to wally666 I'd advise caution in letting this information out.
One thing that I will say is that the GP listing does not have the "box 170" on it. I researched the NAP of the business and found other listings where it was used, but the GP listing didn't have it; just that "base" address.
Here's the problem. The absence of the "box" number, and the fact that the base address is being "shared" with another business (we could call it the "host" business), it's possible that you've watered-down both the NAP of your business as well as the host.
I had a situation a few months back where a well-established business moved from one side of a marina to another, kept the same base address, changed their "suite" number, failed to update all the local listings to reflect the change, and additionally there were other, competing business confusing the situation as they appeared to share the same addresss (both old and new) with the "moved" business, as well as an old address from the "moved" business from years before.
Meaning that the moved business had 3 different addresses showing in local search results, and 2 of them had multiple businesses associated with them.
As a result, the business fell off Google completely, to about page 7 from the top 3 listings of page 1, costing the business owner THOUSANDS and THOUSANDS of dollars. Complete Fail.
Then, in the panic of the drop in rankings, the both the business owner and the "SEO guy" did things that got the local listing completely erased, and they lost years of reviews, etc... and were no longer even on page 7.
Lesson: Don't hire a loudmouth know-it-all to do your Local SEO. He'll buy packages from WF and give you the illusion of having SEO, and in the end it will cost you.
So, back to the topic, I'm still not convinced of two things.
1) That having a "host" address with a sub-address "box" is going to work. I would need to see the suite number listing on GP for a few weeks before I'm convinced that the Google algorithm won't somehow "know" that the box # is fake and zap the whole listing as an obvious fake.
2) That even if it works, that Google will differentiate between the "host" business and the fake business with the box #. Instead of having a legitimate-looking, singular business with "X" amount of juice, you might have a confused NAP with only a fraction of the juice that a business with a legit address would normally receive.
Beyond all of that, if the host business discovers that you are confusing their legit address with your non-legit one, they might cause you serious problems. If, for example, I were hired to do Local SEO by a business that had a legit address and I discovered that some other business were confusing my client's NAP, I'd be merciless in punishing them for doing this and degrading the effectiveness of my client's SEO.
