While directing marketing and sales dollars on phone based email and direct mail campaigns are a necessity to most businesses, wasting them by running them on poor quality unverified lists or contact databases would rank on the seven deadly sins list somewhere between greed and sloth. If your business contact lists have been sitting a while before they were actually put into use the chances are a good percentage of those contacts are no longer active contacts and you will still incur expenses on every phone call attempt made to them, every mailer sent to them or every email that bounces or remains unread simply because all those contacts were dead ends to start with.
Using a list verification service on your sales data before running campaigns on them may involve a small initial cost to get done but will leave you with a verified list which will give you better results, clearer metrics of your success rate on the list and help you cut costs by preventing waste of time, resources and money that would have been put into connecting with business contacts who were either unqualified or no longer in those roles. Depending on what type of campaigns you intend to use your B2B list for, verification can be done for contacts, roles, addresses & location, phone numbers, titles or any details which are essential. If you have a new recently developed list for your campaign where you can rely on its quality then go right ahead but the next time you plan to use a list which you are not too sure about consider getting it verified and you'll be happy with the results.