Most efficient for whom? Spamming is efficient for the spammer, but wasteful for everybody else.

Parasitism is very efficient for the parasite. Don't seek just to make money efficiently, or you'll end up a parasite. Instead look to create value as efficiently as possible.

If I want to improve the economy or the world in general then there are much better ways of doing that than to make sure that all my economic transactions are net-positives for the economy. For example, donating some parts of my profit to an efficient charity would be hundreds of time more efficient towards the goal of improving the world, as compared to making sure that my software creates "value".

If that's your philosophy then why bother following the law at all? As long as you don't get caught it's ok right? There's a ton of money in phishing, scams, and money laundering, why not do those?

Risk to reward ratio is too high.

Shockingly incorrect. You're letting the convenient fiction of money (plus shoddy accounting) confuse your thinking. Value is the only thing that matters.

Suppose you spam your way to a million dollars selling fake Viagra. You have created no value. Your customers have all wasted their time. You've also wasted 100x the time of people who didn't buy. There's more waste in computing capacity and bandwidth, plus the time sysadmins spend fighting and cleaning up after. The resources spent hosting and sending the spam were wasted, plus the time and resources spent making fake pills and fake packages.

The general rule of thumb for business is 10% profit on expenses, so let's assume you had to burn $10m of your own resources to make your $1m. Spamming, though, mainly shifts costs elsewhere. Guessing a 5:1 ratio, let's say you wasted $60m to make $1m.

If we suppose that you're a generous parasite, you'll give 10% to charity, 100k. 25% overhead is very good for charities, so we'll say $75k of resources end up improving the world out of the $60m you wasted. Rather than being "hundreds of time more efficient", you're closing in on 100x worse.

Another important aspect is reputation. When you build a strong business that provides value to people you'll gain a reputation for precisely that. And when you move on to another business that reputation will carry over. When you instead try to be a parasite on the system you cannot build a brand, you cannot afford to let a reputation follow you, and that comes at a pretty big cost to any business venture you do.

I'll ignore the fact that fake viagra sold by spammers is just a generic version of the drug that works just as well, since that wasn't the crux of your argument.

Just talked to my friend who was one of the top spammers in the world. It only takes about 3 or 4M emails to bypass the spam filter for a spammer to make $1M. You're vastly exaggerating the wasted resources in terms of sending these emails, the money spent by customers, the time wasted by people receiving these emails, and the productivity lost by the workers.

$100k given to a charity like VillageReach (http://www.givewell.org/international/top-charities/villager...) on the other hand, will avert 100 infant deaths.