Remember that everything is based on perspective. Well, we have to use combinations of keywords. In the example above you may notice that we used the plural of our keywords. Now the studies that we have done have shown some improvement on using plurals and no negative impact. So when creating keywords use common sense and don't repeat a keyword hundreds of times in the keywords, description and page content, you may find this to adversely affect your positioning.
Many developers try to put every possible word under the sun into their tags and description.
We do recommend that you share them with your staff or friends before publishing them to your page.