Search engine optimization makes your website easy for both users and search engine robots to understand. For every website/blog SEO must need to increase traffic. It's very difficult to increase your blog traffic without SEO. SEO helps derive quality traffic to your blog. For any successful business quality traffic is more important.
After publishing content on our blog, generally we get traffic to our blog when it appears on Google. We can't get traffic to our blog easily if our blogs not appear in first results page on Google. Blogs can't appear in first page on Google easily. To increase search ranking in Google you need to apply SEO techniques.
Fast indexing is must need for website/blogs to get traffic fast. Especially for news related and dynamic blogs, SEO must need. For news related blogs, fast indexing must need. Suppose of you have blog related to news and posted today's news on your blog, if your posted content not appear in Google at that day then there is no use. So to make your articles index fast on Google you need to use SEO techniques.
Type of traffic your blog gets is more important than the amount of the traffic. Even quantity still matters, quality is more important.
Website/blog gets majority of traffic by the major search engines, Google, Bing, and Yahoo!. So to drive more traffic to your blog, you need to increase your blog visibility on search engines. Today social media also playing major role in driving traffic. So you need to apply some SEO techniques to drive traffic from social media sites.
If two websites have same products to sell then the search engine optimized website is more likely to have more customers and make more sales than other websites.
With SEO you can target specific countries. Suppose if you need traffic to your blog from US/Canada, then you need to target those countries with SEO. This is also one of the important factor of SEO.