The best results come from the most relevant keywords to the products and services being promoted. Google assesses how relevant the keywords, ads and landing pages all are to each other, giving favour to campaigns where all three factors are closely aligned. A mixture of keywords should be chosen based on various factors. Keyword research demonstrates how popular particular search terms are with users, but this should always be weighed up against what competitors are doing, along with the likely cost and conversion rate. For example, a particular keyword might be the most relevant for the service being promoted, but it’s also the one which every competitor uses in a highly competitive market. This drives the bid price up, resulting in a very expensive cost-per-click. Based on the overall ad budget which the business can afford, making an acceptable return on investment, just isn’t feasible. It would be better to also include less popular, cheaper keywords, which may cause the ads to show less often, but are more likely to grab users’ attention and convert, based on the lower competition. If a business has USPs or niche services, this approach can be highly lucrative.