There are a few ways to make it work. First off, you need to be using the right ship with the right fit. People like to fly around in Talwars and Thrashers for their suicide ganks. Which is fine, but a Catalyst is cheaper. Another thing I've seen a lot of new gankers try is fitting T2 stuff. If you're guaranteed a ship loss, why waste the money on T2 mods? A meta4 fit catalyst (fits can vary a bit) with the right skills and implants can take down a fairly well tanked Hulk before the Concordoken. All together, I usually never spent more than 3.5mil on my Cat fits. The implants can be pricy depending on where you buy them, but you can avoid having to replace implants by warping to a safe spot immediately after the Concordoken, then dock up as soon as is safely possible (I use the term "safe" relatively, of course).

Secondly, when you loot the wreck in your alt, you want to be looking for something specific. For me, it was the strip miners (especially the T2s). Skiffs and Procurers aren't the best targets because they only have one high slot, so unless they have strip miners in their hold (which is unlikely) you're only going to get one strip miner from them. That's assuming the strip miner drops, of course. Then what you do is sell the strip miners BACK to the miners on the market at an elevated price. It's important that you at least sell them in the same region that you ganked them. No point in selling to miners who you aren't ganking. Naturally, the requires you to gank a LOT. Ganking with a pirate corp will help a lot, too. The more people there are ganking strips, the higher demand there will be for strips. The higher the demand for strips, the more you can inflate the price.

Sorry if this isn't the algebraic answer you were looking for, but that's basically how it works. Basically, you're stealing a ~3.6mil (Hek prices) lolly-pop from a toddler and selling it back to them for 4 or 5 mil (or what ever you've managed to elevate the price to). Considering the meta4 Cat only costs a total of ~3.5mil, you're making a decent amount more than you're losing. Even if you only manage to sell one strip miner for the normal price of ~3.6mil, you're still making more than enough to replace your loss. I hope this helps you to understand the profitability of suicide/hisec ganking. It isn't exactly the most lucrative profession (especially when the miners catch on and won't come out to play for a few days), but it gets the job done.