Consider the average cost-per-click in your industry. Before deciding that SEM is right for your business, research and consider how much you’ll need to spend to show in paid search results. Keywords have varying cost-per-clicks based on competition. If your cost-per-click is low, it might be the right strategy for you. On the flipside, a very high cost-per-click might make you decide you’re better off focusing on SEO.
Now, some buckets are worth more than others, and the three main buckets that you need to be aware of for search rankings are quality, trust and authority. So quality: what Google is trying to measure when they’re trying to figure out what sites should rank is offering something valuable or unique or interesting to googles searchers. For example: good content—if you are selling t-shirts and you are using the same description that every other t-shirt seller is using on their website then you are not offering anything unique to Google’s searchers.
Optimizing a website may involve editing its content, adding content, and modifying HTML and associated coding to both increase its relevance to specific keywords and remove barriers to the indexing activities of search engines like Google ,Yahoo etc. Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.