This type of spamming benefits the spammer because the free link improves the spammer site's search engine ranking owing to link-counting algorithms that search engines use.
A new spam is happening in the digital world, especially in Google Analytics data Called Ghost Spam & Referral Spams with 100% bounce rate. Ghost spam traffic directly interacts with Google Analytics data with measurement protocol system where as referral spam directly influences website traffic. As a result spammers try to increase traffic to their websites.
As with e-mail spam, referrer spam may be filtered or blocked. A website operator may mitigate referrer spam by preventing search engine spiders from crawling the site logs by moving them to a non-public area such as a password-protected area, by using a robot exclusion file, or by appending the nofollow value to the links.
It is found that while some referrer spam pollutes analytics statistics directly, some spammers actually hit the web server. Filtering referrer spam from analytics tools will hide it from the reports but can still continue to consume server bandwidth.to save server bandwidth spammers can be blocked using for example a .htaccess file.
Some information in this article was taken from wikipedia.org.