SEO (websites search engine ranking) is a very broad term and it has now transformed into a complete industry. There are many types and methods of doing SEO including free SEO, paid SEO services, backlink generation, social media marketing, article marketing, article submission, directory submission, press releases, commenting, blog posting, guest blogging, video marketing, and many others. SEO also requires changes in the source code or content of the website. Improper use of SEO services may lead to increased clicks and visitors initially, but search engines may block or penalize the website.
Hence, it is strongly recommended to avoid using illegal methods for promoting your website or blog. Always use white hat SEO services.
Sooner or later, Google is bound to catch up with you is you have been using black hat SEO, web spam or other illegal SEO methods.
And you are best advised to forget any reference to using web spam techniques for pushing up your website else you will be banned by Google permanently. I recommend using white hat SEO services whether it be paid or free SEO. You should find genuine ways of promoting your website keeping in mind the new Google algorithm changes. Your efforts will not go to waste since those who have been waiting to duplicate content are being dealt with in the proper manner. Do the right thing and be on the safe side.