Link: Letter from Lowe's (95KB scanned image).
Lowe's spammed Dave Lugo with unsolicited email. Dave complained, because he never gave Lowe's permission to email him. Instead, Lowe's probably acquired Dave's email address through means such as web scraping or e-pending. Lowe's responded to Dave, pretty much saying, "Our shit doesn't stink."
Here is the problem: Lowe's acquired Dave's address, but they never acquired Dave's permission. Lowe's performed a mass emailing to people without ever having their permission, and that, my friends, is spam. What's worse, not only is Lowe's email campaign unethical, it is outright illegal in many states.
This gives the potential Lowe's customer pause to consider. First, Lowe's is in denial regarding their offensive marketing policies. Second, they stand firmly behind their "opt-out spam" policy. Finally, they engage in unethical--and possibly illegal--marketing practices. If the cost of doing business with Lowe's is more spam in my mailbox, then I think I'll shop elsewhere.