Organic search is extremely important for online retailers, as many studies suggest it drives around 50% of website traffic. When it comes to search engine optimization for eCommerce, marketers get obsessive about testing all methods available to them to try and achieve higher rankings. The logic is very simple: higher positions on SERPs automatically result in higher impressions and a significantly better click-through rate. More people visiting your store should ultimately translate into better conversions and higher revenues.
I think for agencies as far as how we appear in organic search ourselves, we are definitely going to need to leverage all 3 of the solutions you talk about and agencies who haven't branded their products/services are going to have to do that and are going to have to also employ branding strategies. In addition, we have to optimize for other search ares like you say in your point #2 and we must look at optimizing existing content for voice search and answers/featured snippets like you say in point #3.
Plan your link structure. Start with the main navigation and decide how to best connect pages both physically (URL structure) and virtually (internal links) to clearly establish your content themes. Try to include at least 3-5 quality subpages under each core silo landing page. Link internally between the subpages. Link each subpage back up to the main silo landing page.
BrightEdge research supports that a blended approach is best for delivering high performing content. Not only will combining organic and paid search increase website traffic, but it will offer a bigger return on the investment. Take Retail, Technology and Hospitality industries, for example — organic and paid search combined make up more than two-thirds of their total revenue.