No, never! But if you need the "why", let me tell you. People on a purchased list didn't choose to hear from you or your company. The goal of your marketing efforts should be to find the right prospects and customers. If you buy a list, you are taking that decision away from your prospects. Suddenly, they receive this message from you (or their spam folder, most likely), but have no idea what it's about, who you are, how you got their information, and now you're on their bad side. So just don't do it, ok?