Recent research indicates that up to 90% of Internet email is spam. Even now, those in the blogging world are noticing an increase in the levels of comment spam. The problem stems from the fact that the folks behind this deluge of virtual dung win each-and-every-time they successfully circumvent a spam filter and someone clicks on an link, replies to the message, or purchases a stock. Even worse, there is an inherent benefit to some spammers in simply sending the message. The fact that they don’t receive a bounce-back is an effective way of validating good.”]
Source: https://www.csoonline.com/article/2136771/spam–give-me-a-break.html