Keyword research plays a crucial role in both SEO and PPC to appear in SERP and rank in a top position. However, separate keyword research may not be necessary for both methods as using an existing SEO keyword list can burn money in PPC.
To filter keywords for each, it is best to think about the marketing and keyword funnel. SEO and PPC can create any stage of the marketing funnel, but it is better to narrow down keywords in PPC that can lead to conversions. The keyword funnel consists of three types of keywords: informational, commercial, and transactional.
When using SEO for creating organic traffic, all three types of keywords can be used. However, when doing the same thing with PPC, targeting an audience with informational keywords can be challenging as they reach a broad audience rather than the targeted audience, resulting in a lower conversion rate. In contrast, commercial and transactional keywords have a higher conversion rate and can lead to better results.
Another difference is that CPC is not considered in SEO, but it is important in PPC.
In conclusion, whether running a business using SEO or PPC, it is better to focus on the number of conversions or leads that can be converted into conversions.