I was looking for something, and ended up in a set of pages at

amazon.ca where most pages of stuff, were things that were "on

target". So, I waded through 20 pages of ads on items for sale.

There were a few (2?3?) main sellers or what I was looking at, and some

minor ones.

If one just looked at one seller, they had ads for 1 item, 2 items, 3

items, 5 items, 6 items, and so on. And the price per unit varied.

Fine. What random distribution that is readily available, occurs for

positive real numbers and has finite variance? Probably lots of them,

but lognormal is common.

my $cost = 0.15;

my $markup = 0.3;

LOOP:

my $z = random_normal( 1, 1, 1 );

my $n = random_poisson( 1, 2 ) + 1;

my $unit = exp( log( $cost * (1 + $markup) ) + $markup * $z );

$unit = int( ($unit + 0.005) * 100 ) / 100;

my $bundle = $n * $unit;

print "Selling $n for $bundle\n";

goto LOOP;

which as written, loops forever. In 100 trials, I had 2 bundles sell

for (slightly) less than cost, and the incoming revenue from all the

sales was almost twice the cost.

Some item pages had statements about inventory, which could be real or

not. This process can generate bundles of number and price that have

been seen before.

What it does, is make it possible to be seen by the shopping public

many more times, than if you just bundled up everything into 5's and

sold them at one price.

Not every shopper is going to look at all pages to see the totality of

ads you have. They may look enough to see that you have the same

number of the same item multiple times. Does this stop them from

shopping at your "store"? I would imagine that some of your items,

with the higher per unit costs don't see as fast as the lower priced

items, but do they all sell eventually? Or do you have to "pull

inventory" and selling them at a lower cost?

I don't know that sellers are doing this, but it sure looks close to

what my Monte Carlo model came up with.

--

Gord