Never Buy A Mailing List

This should go without saying but I have come across far too many businesses who are proud to have a mailing list of thousands but they are worth nothing as they paid an agency for those lists.
Let me be blunt, never ever purchase a list, or build a list for that matter, of potential ‘customers’ who have never opted in or never even heard of your brand.
You are wasting your time and money trying to market to these people when you could be focusing your efforts in building up real relations that will have a better chance of converting.
Not only that, you are breaking data protection laws and could be heavily fined in the process.