Georgia Christian, who is the editor of an online marketing service, is one of the individuals who has been discussing this exact point.
In an article for memeburn.com, she explained that firms will be financially better off letting go of subscribers who have been inactive for a long time.
She added: "It's difficult to let go of a subscriber and their valuable details when they start ignoring your email campaigns. Sadly, this will be the email that will get them interested again, I hear you ask yourself. Sadly, this is rarely the case."
Crystal Gouldey, an experienced education marketing associate, has pointed out that a huge list of inactive subscribers could also affect a company's deliverability rate, meaning that more of the emails end up in the junk box.
Writing for business2community.com, she said: "ISPs are looking at engagement more and more when they decide to deliver an email to the inbox or not. This means if your list of addresses that aren't responding, you can see lower deliverabilty."