Your promo night needs 113 people. Did you know that before you booked the DJ?

Most promotions get judged the next morning by how the room felt. It was busy, so it worked. It was quiet, so it did not.

That is not a measurement. It is a memory.

Here is the version that actually tells you something, and it takes about ninety seconds before you sign anything.

Start with what the night costs you

Not your rent. Not your manager's salary. Those get paid whether you run the promo or not.

What you want is the money you would not spend if you cancelled tomorrow. The DJ fee. The extra door guy. The printing. The 200 dollars of giveaway. Add those up and you have the real number the night has to earn back.

Say it comes to 1,200 dollars.

Then work out what one guest is worth

Take what a guest spends on a normal night. Say 32 dollars.

Subtract whatever you are giving away. If the offer is a discounted first round, and that costs you about 6 dollars a head, you are collecting 26.

Now subtract what it costs you to serve them. Product, hourly labour, card fees. For most bars that runs somewhere near half of what they spend. On a 32 dollar guest that is around 15 dollars.

So: 26 dollars in, 15 dollars out. Each guest leaves you about 11 dollars.

Now you have the only number that matters

1,200 dollars of cost, divided by 11 dollars a guest, is 113 people.

Not 113 people in the room. 113 people who would not otherwise have come.

That distinction is where most promo nights quietly lose money. If 90 of your regulars show up and take the discount, they did not earn you 11 dollars each. They cost you 6 each, because they were coming anyway and you just handed them a discount.

What to do with the number

Write it on the booking before you agree to it. Then ask one honest question: does 113 new people sound like this DJ, this flyer, this Tuesday?

If it clearly does, book it.

If it clearly does not, you have three options and all of them are better than running it anyway. Cut the guarantee. Cut the discount. Or move it to a night where 113 strangers is plausible.

And if you genuinely cannot tell, that is useful too. It means the night is a test, not a plan, so treat it like one: run it once, count the door, and find out.

The part nobody does

Count it afterwards.

Not the vibe. The number. How many people came, roughly how many were new, what they actually spent. Ten minutes with the POS report the next day.

Do that four or five times and you stop guessing about promotions entirely. You will know what a Tuesday costs, what a DJ is worth to you, and which offers pull strangers instead of subsidising regulars.

That is the whole thing. One number before, one count after.

Run the numbers on your own night: the promotion break-even calculator does the arithmetic above with your figures. Free, no signup, and nothing you type leaves your browser.

Run the Room is written for people who operate bars, restaurants, and venues. Reported facts link to their sources. Modelled examples, like the numbers above, are labelled as models. If we get something wrong, tell us and we will correct it in the open.