Sure, it can be worth the time, but it depends on how you spend your time doing it. You can pay others to post content of other forums and blogs for you with links leaning back to your site, or you can do it yourself. Either way, if you do decide to do so, then it's best to diversify the methods as much as possible so you can look as natural as possible. The more natural you are the better you are viewed by the search engines.

Link posting is good as it will get you more backlinks which will determine your search engine ranking too.

Could you please explain, this link posting? Where are you going to post links?

By using the phrase' link posting', I'm assume you mean link building. And if that is what you mean, link building. it is very important for SEO and can help your site achieve better rankings faster than any other SEO activity.

Link posting i.e., submitting your website link on other high PR websites is really helpful for building backlinks for your websites. It is popular SEO technique that helps in improving ranking of your website.

Link Posting can be very crucial for promoting your web site:

It provides High quality incoming link means your site will be admired as a valuable resource. This could be easily done by writing quality content.
Link building also helps in getting indexed in search result easily.