No matter what vehicle you use to create exposure to traffic for your sites, you will want to include keyword phrases to help the search engines rank the site for the niche traffic you want. And, in any of these third party submission archives, you should check google keyword rank be asked for keyword phrases, whether they refer to them as tags, categories, or titles. What you want to do is weight (or give more weight to), the content so that the search engine finds it easy to understand and rank for your particular topic.
Of course, you shouldn’t seek to overdo this practice as it can count against you too. Using the same keywords over and over again is considered keyword spamming by the search engines and can actually cost you position ranking in your SERPs. But, keywords rank checker generally, you can add a keyword in the title, some in the tags or indexes, categories, and some within the content too. It generally depends on how large your articles and or press releases are as to the number of instances a keyword can be inserted without triggering a Google penalty to your positioning.
If you have less than 2% of the content as keywords in the body of your content, you are typically safe. For that, there should be less than 2 keyword phrases per 100 words written, counting the title, headings, and subheadings.