How much traffic for a local business site?

I have a question for those who are actually getting a paycheck for this. If you set up a blog to attract clients for a local company, like a chiropractor. How much traffic do you like to see for the related search terms, for which you want to rank?

Thanks

for local business i look at terms that are getting searched at least 100 times a day. If you can get them into the top 3 that is way more traffic than what they have been getting. Now the next task is to get it to convert.

Thanks