The keyword alerts is too vague. I think the estimated daily clicks is based on the CPC and the competitors you'll have to face if you choose to bid on that key

The keyword alerts is too vague. I think the estimated daily clicks is based on the CPC and the competitors you'll have to face if you choose to bid on that keyword. Because personal search is more specific, you might actually get up to 19 clicks per day based on the estimates that google gives you.