Go to your Keywords tab, and select that single keyword, Go to the Keyword details tab, and select "Auction Insights". This will give you a bunch of useful information:
- Impression share: How often you ad shows up
- Avg. position: The average position of your ad when it does show up
- Overlap rate: You can see how often your ad appears vs. other advertisers
- Position above rate: How often you're ranking above other advertisers.
- Top of page rate: How often you're at the top of the page (vs. the side).
So if your average position is already between 1-2, and your impression share is high, raising the bid probably won't do much. However, if you're not at the top of the page much, or your impression share is lower, you might be able to get more clicks by raising the bid.
