The Ultimate Guide getting 1st position with Rich Snippets
Rich Snippets are ways Google enhances search results for a given query. This might be showing reviews based on stars or highlighting the knowledge graph query.
Rich Snippets can be added in HTML of your template. There are many WordPress plugins available for this. Otherwise you can add them yourself by learning more about them.
Rich Snippets can increase the traffic to your site. They are also considered to Ranking Factor by some SEO Agencies.
Use Rich Snippets whenever it makes sense to use. If you are running an e-commerce store or any informational site like Recepies, definately use them.
Have you correctly added the tags. You can check your page on any Rich Snippet Preview Test Tool from Google or Bing.
It takes time of search engines to index your site and then display snippets. The more PageRank/Trust Flow/Citation Flow a website has, the earlier it will starting showing Rich Snippets.
You can use Rich Snippets testing tools in Webmaster Account from Google or Bing.
Wordpress has many plugins that help you in this regard. Otherwise you can also add them manually if you know some HTML. You can also get it implemented by some programmer for your site on the cheap.
Rich Snippets enhance the result on your page which are most relevant to the user performing the query. The more relevant the answer looks to them, the more traffic they will bring to your site.