Keyword research tools like Keyword Planner seem to fulfill two basic functions:
- Generate a list of possible keywords
- Provide estimates (CPC, traffic, ...) to whittle down this list to the most effective keywords
Do I need the second step? Is there any downside in uploading a huge list with thousands of keywords and just wait and see how they perform? It's pay per click so I'm not losing money on low performing keywords.
Ultimately I'm only interested in conversions and that's a metric that can't be estimated by the tools anyway.
As Joshak points out, I need to remove all obviously non-converting keywords. What about other keywords that could theoretically convert but the estimates show it's unlikely. For example 0 traffic or very high cpc, so it's unlikely I will win the bid. It would be more work to remove them and there are slight changes that they bring conversions. Is there any downside in using them?