Additionally, there are many situations where PPC (a component of SEM) makes more sense than SEO. For example, if you are first launching a site and you want immediate visibility, it is a good idea to create a PPC campaign because it takes less time than SEO, but it would be unwise to strictly work with PPC and not even touch search engine optimization.
SEM search placements include an “Ad” designation. SEO does not. Search results that appear as a result of SEM or SEO look different on SERPs. Paid ads that receive placement through SEM tactics are often identified as an ad (e.g., by an icon appearing next to the placement), whereas the search results that appear as a result of organic SEO are not marked in such manner.

Fill this bucket by building a fan base. Build a social network, get people to link to you, get people to share your t-shirt pages on their social network saying ‘I want this!’, get people to comment, leave testimonials, show pictures of themselves wearing the product or using the product, Create a fan-base and then rally them to link to you and talk about you. That’s how you prove to Google that you are trustworthy and authoritative.

Everything for Google these days comes down to “Customer Experience”. Page speeds, table of content, the relevancy of content, length of content, uniqueness of content, jump links, video in the content, relevant headers, less broken links, customized 404 pages etc are all indicative of improving customer experience on th website and hence helps you rank better.
Webmasters and content providers began optimizing websites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters only needed to submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed.[5] The process involves a search engine spider downloading a page and storing it on the search engine's own server. A second program, known as an indexer, extracts information about the page, such as the words it contains, where they are located, and any weight for specific words, as well as all links the page contains. All of this information is then placed into a scheduler for crawling at a later date.