This can work if the cost per email is low enough, the open rate and click through rate are high enough and the offer has a high dollar amount. The response rates to these type of campaigns is really low, so whatever you are promoting must be high priced and high margin for you to get positive ROI.
However, there are a few important things to note:
Have the list broker email on your behalf. Never email from your domain since you do not know how the list was built. Every broker says their list is double opt-in but that is rarely the case. Even if it is, the email owner agreed to receive email from the broker not from your company and so you may get spam complaints. If there are enough spam complaints, your domain will be blacklisted, a very bad thing!
Vet the list broker thoroughly and ask to see some campaigns they have run.
I would name some list brokers you should avoid but I don't want to get sued! Email me privately, if you would like recommendations.