But seriously, you make a very good point. Sales projections are tough and they almost always fall short. And the first sale can often be the hardest since the product is unrefined and you have no brand or previous happy customers to point to. Thanks for the comment.

But seriously, you make a very good point. Sales projections are tough and they almost always fall short. And the first sale can often be the hardest since the product is unrefined and you have no brand or previous happy customers to point to. Thanks for the comment.

For flights – how much per hour of flying am I paying? It makes a 23 hour flight to Bali that costs $950 right now look pretty good!

For utility items – a cup of coffee, takeout rather than cooking. What is my time worth and the cost to make it myself. Sometimes if I'm busy it's worth it. On the weekends when I'm not earning with my time, it isn't.

I think it's great to look at businesses in the same way. You avoid getting yourself into a situation like paying $54,000 a month for rent to sell hot dogs! http://www.huffingtonpost.com/2009/08/08/hot-do...

Of course, that's just basic living expenses. You don't live in NY to sit in an apartment and look at 2 square inches of sky every day. There's $50 binges at the bar, Hampton's or Jersey Shore weekends or skiing holidays. Additionally, New Yorkers are pretty social and sexual, so there's going to be plenty of dates. Keeping a date under $100 is a battle.

That is one of the real downsides of living in NYC, it almost doesn't matter how much money you make, you're being sucked into bankruptcy.

Otherwise, why not start a soda company in China? Just 1% of that market is 12 million people.

A wrinkle to this would be products that have highly variable and or infrequent rates (or worse, both).

Your iphone app probably sells at a fairly constant rate (when you're not spiking on press releases due to initial launches and upgrades). So if we take your assumption on rates (and your $100/day bench), and say you sell ~25 apps per day, I'd imagine that rate to be fairly constant. i.e., day to day flex of say 0 min to 25 max, with weekly variances of +/- 5 or 10% week/week. So you've got a product that sells frequently and consistently, and can think in pretty clear terms of daily rates.

However, I know the Atlantic Avenue section you're speaking of well, and you can take a look at some of the dress shops there that have like 10 dresses on display in the whole store. These guys probably sell 5-6 dresses a month for $1000 each. Clearly trying to think of this rate on a daily basis will do you no good (I'm selling .2 dresses/day!). You're limited in using the rate to plan cash flow, because a bad month could mean you're operating in the red, while a good month means you're way, way in the black. To cope with one extreme, you've got to keep a lot of cash on hand to cover dry spells–hurting your ability to invest in new products. On the other, you're faced with an inventory issue–if you do sell 500% more dresses in a month, will you be able to find supply for that demand?