Gross Operating Income (GOI)

Randy, I think this is an interesting little calculation, and am wondering if it can be made to be usable. Perhaps you have more input on this.
My question stems from the statement that the investor would "compare them to other properties available in making a purchase decision."
How would an investor derive that information unless they have been researching a series of properties and running this calculation on each of them? I guess I could see the formula as another way of comparing a subject property to other available properties they are considering.
The standard methods of comparison using Net Income (Cash Flow), Capitalization Rate (CAP) and Cash on Cash Return seem a bit easier to use as comparison methods, as it is relatively easy to find an agent, or a property manager who can share with you the average Cash Flow or CAP Rate on a particular type of property in the area, and comparing your ROI vs. other types of available investments is relatively easy too.
Maybe I have answered my own question, but I value your knowledge and opinion, and perhaps you have more input or understanding on this than I do.

is the other one like calculating the gross annual revenue?

Dont overlook the future repairs:

Roof, appliances, flooring,window/doors, kitchen and bath upgrades that WILL cut deep into the numbers

Mike, I'm hoping Randy will offer some additional insight. Your point is well taken in regard to deferred maintenance and needed repairs.
I would say that this formula is probably designed as a quickie formula that makes certain assumptions, and would not be the basis for making any final decisions, but can be helpful to an investor at an early point in property analysis. I suppose it would be like the larger coarse filter that one might filter water through before the fine filter that takes out the smaller impurities--as we look at properties, we have to filter the long list down to the short list, and then do more diligence on the short list to decide which property we would like to purchase.
Femailceo, I think the gross annual revenue would be another quickie formula for filtering properties.

Yes, I now know my buyer wants more than the Gross annual revenue as well. He for instance wants gross annual room revenue for hotels and considers extra revenue the hotel makes the gravy on top as he put it! I however sense that you are implying there is more to the gross annual revenue?

I also hope we hear more from Randy.

Hi, it's not necessarily my intent to imply more on gross annual revenue. When I refer to a quickie formula, I'm referencing information that is either quick and easy to obtain that you can use for apples to apples comparisons, or that is the kind of calculation you can do in your head to decide whether you want to pursue that property further.
As an example, many investors are familiar with the 1% "rule." This quickie formula says that if the monthly rents on a property are equal to or greater than 1% of the purchase price of the property, you are more likely to have a positive cash flow.
I certainly wouldn't make any final decisions on the basis of this calculation, but I can tell you that if a seller tells me that their gross monthly rents are $1500 on a $100k property, I'm a whole lot more interested in that property than if they tell me that their gross monthly rents are $500. I can run those numbers in a couple of seconds in my head rather than pulling out my calculator and trying to run a cash flow analysis followed by a CAP rate. BUT, as we all know, we are ultimately going to need to run the Cash Flow, CAP, and calculate our future ROI, and we're going to need additional data and time to do that.
Hope that explains my take on gross annual revenue, or any other quick comparison numbers or calculations that we can use on a property.