Platform vendors
joelonsoftware.com
joelonsoftware.com
It seems to me that Microsoft takes great pains not to add features to their operating system that are implemented by independent software vendors (Windows Security Center), whereas Apple will just add the features (Leopard Application Firewall v. Little Snitch).
The only good advice (which the article seems to avoid saying) to be realistic. Everything has a useful lifespan after which no one wants it (or they want it at very near the cost of producing it). Be grateful that you can potentially predict that lifespan and not over-invest in that project.
"Filling little gaps in another company’s product lineup is snatching nickels from the path of an oncoming steam roller."