Nowadays is important to have a keyword strategy when writing new content, as such, a tool like google keyword planner helps in establishing what are the main keywords that you want to cover.
As such keywords, the strategy is twofold, either go for long keywords (3 or more words), or short keywords (1 or 2 words), which are more marketed, but is more difficult to obtain audience.
These strategies, help in defining the niche that the blog covers. For example, when writing an article about sports car, is good to specify also the type of car, and the engine. By having more keywords when writing an article, is possible to be found more easily by search engine, such as Google or Bing.
Whenever I write an article, I tend to look for keywords that are mostly used, so that I can target my audience with specificity and detail.
This strategy is used by many bloggers, and help in defining what to write, and gives some ideas on what to write.
Long Keywords are helpful as when writing, deviating from the topic and going off topic becomes more difficult.
Using Short Keywords, is more competitive and more difficult, as the search engine spawn many results, and usually the attention span of the user of the search engine, is focused on the first 3 results, or Search Engine Results Pages (SERP).
The use of long keywords, is also suggestable when creating ads campaigns, as it allows to avoid to spend too much budget on digital marketing campaigns.
Not that Digital Marketing Campaigns are not important, but the problem rely in the cost of such campaigns.