Continuing our series from 2012 where I accidentally ended up combating phishing and fraud for a year, we move onto the spam issue. Everything that happened that year was an exercise in triage. Problems were everywhere on the system and in the marketplace. The site I was working on was the leader in a niche space but it wasn't just the phish who tried to capitalize on the chaos, it was our competitors too.
Spam takes a time investment and every time investment is a business decision. If you can't stop it completely, you can at least dramatically increase their costs...and have fun doing it.