I monitor my lawn very closely after seeding. Any areas that don't come in that well I throw down more seed. I usually get germination in 4-5 days, so if it's not up in a week or 2 I throw more seed down.

Are you throwing down some soil on top? I just overseeded as well, and this is what I do. If it's a big spot (bigger than 1 foot), I dig it up to at least 6" deep to loosen the soil. Then compact it very lightly. After I seed, I sprinkle a very thin layer of top soil over (1/8" - 1/4" max) that way it doesn't get direct sun.

Works like a charm everytime. Obviously you don't have to sprinkly dirt when you overseed in grassy areas (since the grass provides the sun protection it needs).

There may have been a lot more thatch than the aeration job took care of. It wouldn't have hurt to rake the thatch away so that the seed was in better contact with the soil.
I agree,the topping with some compost/topsoil may have helped the seed start well. The starter fertilizer would have/should have helped as well.

When you say, you watered twice a day....EVERY DAY? and how much water....the seed should be kept damp for a short time, then the amount and times of watering is cut back.
The seed might have a type that takes a little longer than the package says it will--give it some time.
If you feel its not working, then go ahead overseed again...it sure aint going to hurt.

Yes watered it twice a day, every day, maybe a little too much. But since i posted this, it seems most of the grass has come in now, i just have a few bare spots where that i probably need to rake up like jordanz said. i have some Lesco EZ Lawn which i think i will put down. thanks all.

>"or wait and hope it fills in?"

How can anyone answer this for you not knowing what you seeded or where you live?

Did you use an starter fertilizer?

KGB + fescule mix, North NJ, and yes i used a starter fertilizer.