This has nothing to do with how much money they make from alcohol sales. But rather whether you can CC has to do with whether they sell by the glass or just packaged.
There is no such 51% clause in any MI law. But rather the law says.
(d) A bar or tavern licensed under the Michigan liquor control code of 1998, 1998 PA 58, MCL 436.1101 to 436.2303, where the primary source of income of the business is the sale of alcoholic liquor by the glass and consumed on the premises....
Primary source of income and 51% are two very different things.
To sum up.
IF you have a CPL you may CC or OC in any licensed establishment that sells packaged liquor.
IF you have a CPL you must OC in any place that sells by the glass wherein the sale of Liquor by the glass is the primary source of income.
IF you do not have a CPL you may NOT be on the premises of the location that is licensed. (this includes all property - parking lots grass everything)
NOTE while the liquor law specifies premises as the building. 750.234d does not and parking lots as well as all other property would be considered premises. Unfortunately we cannot take the definition from one law and use it in another. So as far as I can tell what Dr. Todd found is interesting but of little use.
Edited to add missing info.
I'm not so sure the "premises" issue is a settled fact so to say it is "of limited use" is your opinion, just as my opinion is that it is useful. Generally, you can't take the definition of one law and apply it to another BUT if one law is based upon another, I think it may be possible. There really is no sure way to know. The safest bet would be not to carry anywhere on the property that has a liquor license if you do not have a CPL.
Since the OP does not have where in Michigan he lives listed and he states that he has a CPL, let's pretend someone reading this does not and let me use my county as an example. IF ONE DOES NOT HAVE A CPL: In Kent County, don't carry at some of the hotels, as they have liquor licenses. Forget about golf courses, too... most have liquor licenses. Banquet and conference centers, The Grand Rapids Art Museum, Schuler Books, Frederick Meijer Botanical Gardens, Grand Lady Riverboat Cruise, East Hills Athletic Club all are prohibited places without a CPL. So, even if it looks like a "safe" place, the only way to make sure is to check the DLEG website and see if they have a liquor license...
http://www2.dleg.state.mi.us/llist/
BTW... "primary" doesn't necessarily mean "majority" as malignity very wisely stated... the term itself is pretty much open to interpretation. So, if one wants to really be safe... it is best not to carry concealed with a CPL in
any establishment licensed for consumption on the premises because, depending on what interpretation a LEO or judge wants to apply to your case, any one of us could be breaking the law. Also don't think that by OCing w/ a CPL you are going to be safe either... BTW, has anyone heard anything regarding that case in Lansing??