Search engines like keywords — I want search engines to like me — Need to add MORE keywords!
This kind of technique is called over-optimization, and it is relatively easy to spot because of excessive consumption of keywords on the website page, or some bold type indication (bold or italic, or even all of them together).
Ironically, but 15 years ago this strategy was highly successful (however, those days have gone, and it’s likely that they’re not coming back). It is not worthwhile to remember a past when we prepared texts such as:
“You can buy yellow rubber ducks on our website, because we have the best price for yellow rubber ducks! Buy yellow rubber ducks online!”.
Well, that was fun, but now such an approach would make your substance unnatural and futile for its target group. Search engine algorithms detect the quality of content, so avoid filler. Search engine over-optimization with high probability will decrease the website position of Google search results (or even a complete exclusion).
How to solve
Remain natural. Do not whip out a calculator to count the number of occurrences. Just take a look at the texts of a copywriter, and estimate its readability and ease of perception by the target user. You may actively use synonyms, remove all the repetitions. Finally, take a thorough look at LSI copywriting (Latent Semantic Index), that would help you to build your web page relevance for search queries.