One has to be a regular to learn about all those deals. I suppose they are available, but I have become very proficient in my own kitchen since Covid hit.
The BK deals are usually on large signs in the windows. You'll also see them online.
Worst default is a regular priced Whopper at 5.99, + a buck to make it a Double. So 6.99 for a Double Whopper - which is a reasonable deal - even with respect to the indie competition.
But seriously, this stuff pops right out on the websites, and usually you can put in your zip code, select your closest store, and immediately see the promotions and other prices.
I'm not otherwise a fan of Dominoes Pizza, but they have one specific unique variety I do indeed like. Ordering online using one of their promotions that's been going on - literally - for years, I get two medium pizzas out the door for under 15 bucks! That's less than half the regular price!
If I wasn't getting the promotional price, I probably wouldn't order from Dominoes in any frequency, or perhaps even at all. But at that price, with as much as I like this specific pizza, I'm hitting them up maybe once a month!
There's a unique one-day-a-week chicken wings combo deal that my local Hooters (of all places) runs, and it too has been going-on for years: 10 bucks for a full portion of my choice of wings, + my choice of side (I go with curly-fries or tater-tots), + my choice of dipping sauce (the blue-cheese kicks). The dipping sauces are surprisingly high quality, as are the wings.
The wings are usually 15 bucks, the fries are 6, and the sauce is 2 bucks. I do indeed like the wings and fries, they're good "restaurant "quality". But I'd probably not pay 20+ bucks for them. I've got another place when I want wings at the full going-rate. But at 10 bucks? I can't say 'no'! I hit them up maybe once a month, and never finish the large portion in one setting.
I buy none of the stuff I mentioned in this thread because "it's cheap". I buy these items because, "I like them". But that I can get them relatively cheaply allows me to choose them over other alternatives that might otherwise dissuade me from choosing them. IOW, if these items were more expensive I'd probably use other alternatives.
There's all kinds of stuff like this available for the taking, if you use a modicum of effort & practice due self-control.
These corps put systems in place. Use these systems to your benefit, not theirs. Good consumerism demands it!