Yes. Ofcourse. You can win only in the condition of team. Otherwise a batsman scores a century but his team loses the match. So his century becomes useless.
If you asking in terms of e-commerce, Magento is the best platform than shopify. The reason that it's SEO plug-ins work very fast and they are reliable.
Yes. it is the most effective technique which is used nowadays. Not every company afford it because t create an infographic is not an easy task. So, focus on it, it will give major boost to the SEO for your website.
Keep in mind the following points:
1. With homepage, optimize Services/Product pages of your website.
2. Consistently focus on content marketing.
3. Strictly follow Google Webmaster Guidelines while optimizing your website.
4. Strictly avoid black hat SEO techniques.