Below, i will demonstrate why paying 20.8m ISK for the Rush Job to haul items from Jita to Dodixie is better than paying 5.8m ISK normal rate to haul the same items from Jita to Dodixie.
Consider the scenario. I have bought 400m ISK of items from Jita, i believe i can make an operating margin of 20% on them when i sell them in Dodixie (i.e. i hope to make total sales of 500m ISK from those items leaving a profit before broker fees and sales taxes of 100m ISK).
I also know it will likely take me 10 days to sell all these items.
I have 3 choices on getting these items from Jita to Dodixie.
1) I can haul them myself - that is the fastest but the least safe but at least all the profits go to me.
2) I can contract the hauling to Push Industries (or anyone else) and pay 5.8m ISK and it will take up to 3 days to get there. And so i keep 94m ISK of the profits before broker fees and sales taxes.
3) I can contract the hauling to Push Industries and pay a premium to get it there in less than 24 hours (often in less than 5). In this case i would pay 20.8m ISK and so keep 79m ISK of the profits before broker fees and sales taxes.
Now, add in one key point - making ISK is a function of 3 things: the profit margin on each sale; how often you sell these items; and how much capital you put into your business. Essentially, profit over time is the profit margin made on sales x speed of sale x capital. And what we want to do is optimise all three parts of that nice equation.
Lets assume i don't haul them myself - takes time that i would rather be devoting somewhere else and over time i will be ganked.
So, lets look at what happens here under the second and third options (and for this example lets ignore broker fees and sales taxes):
Assume i use the normal hual rate:
on day 0 i buy the 400m ISK of items from Jita.
By paying the normal hauling rate of 5.8m ISK i get them to Dodixie on day 3 and put them up for sale for 500m ISK. By day 13 (3+10) i am sold out, making sales of 500m ISK, and so buy them again from Jita for 400m ISK. I again pay the normal rate of 5.8m ISK to get them to Dodixie on day 16 (13+3) and put them up for sale for 500m ISK. By day 26 (16+10) i am sold out, making sales of 500m ISK, and so buy them again from Jita for 400m ISK. I again pay the normal rate of 5.8m ISK to get them to Dodixie on day 29 and by day 39 i am sold out, making sales of 500m ISK.
in all, it took me 39 days to make sales of 500x3 = 1,500, incur buying costs of 400x3 = 1,200 leaving profits of 300m ISK from which i paid hauling fees of 5.8x3 = 17.4m ISK leaving me profits of 282.6m ISK.
and now lets assume i use Rush Jobs instead:
on day 0 i buy the 400m ISK of items from Jita.
By paying the Rush Job hauling rate of 20.8m ISK i get them to Dodixie on day 0 and put them up for sale for 500m ISK. By day 10 (0+10) i am sold out, making sales of 500m ISK, and so buy them again from Jita for 400m ISK. I again pay the Rush Job rate of 20.8m ISK to get them to Dodixie on day 10 (10+0) and put them up for sale for 500m ISK. By day 20 (10+10) i am sold out, making sales of 500m ISK, and so buy them again from Jita for 400m ISK. I again pay the Rush Job rate of 20.8m ISK to get them to Dodixie on day 20 (20+0) and by day 30 i am sold out, making sales of 500m ISK. I again buy the items for 400m ISK from Jita, pay the Rush Job rate of 20.8m ISK to get them to Dodixie and put them up for sale on day 30 (30+0) in Dodixie. By day 40 i have sold them all making sales of 500m ISK.
in all, it took me 40 days to make sales of 500x4 = 2,000, incur buying costs of 400x4 = 1,600 leaving profits of 400m ISK from which i paid hauling fees of 20.8x4 = 83.2m ISK leaving me profits of 316.8m ISK.
. . . . . and these things scale very nicely. If instead of buying 400m ISK from Jita i was buying 2bn ISK of items to sell at 2.5bn at Dodixie, the normal hauling rate would be 11.5m ISK a time vs the Rush Job rate of 26.5m ISK. Running through the above example with these new numbers means the Rush Job option would make profits of 1.9bn ISK vs the Normal Hauling rate of 1.5bn ISK.
In all, the Rush Jobs have ensured i get my items on sale very quickly and so improved my [speed of sale] which has resulted in me making more profit.