One of the most well known strategy for Search Engine Optimization is getting higher page rank. High Page rank means having numerous links from quality websites. Most of the time if the content of a web page is considered unique and sought after there is very high chance that some high quality website might provide a direct link. So the basic theory behind high page rank is get quality content and get links from high ranking websites which ultimately leads to high page rank.
There are several webmasters who have got erroneous belief that if they will put their website link in the comment box of several websites , it would lead to high page rank. Most of the times these webmasters write naive or irrelevant comments on other websites with their website link in the comment form. However, the good news is that most of the blogging scripts which inludes Word Press and Joomla have got inbuilt plugins like akismet which identify these comment spams and list them separately. Most of the time webmasters delete these spams. Even if the links get approved there is very high chance that there would be meta instruction of no listing and no follow so it means that search engine bots would not follow such links.
The bottom line is , spamming can't help in getting high page rank.