I don't think there is a set amount you can definitively expect. You could have 500 visitors and maybe none of them will click on an ad. You'll still get some money from HubPages Ads, but it won't be more than cents. Or you might have 20 visitors but they are all super interested and click on ads so you'll make some money. Also, each ad that is displayed is worth different amounts per click. You might have some that are worth upwards of $5 or some that are worth 50 cents. I've had days where my traffic was really high but only made 88 cents and just yesterday I made over 11 dollars but my traffic was low at around 75 visitors.