The reason I ask is I ordered an item first class yesterday and the delivery estimate said it would come today, so I waited in all day and it had not showed. I am not worrying too much - yet - as it has only been a day, but I am just asking about the estimates in the case there is something possibly wrong?

Thanks guys.

They can vary from a few days to maybe a week, although if your post office is not very good (like mine) then it could be longer.

I actually tend to get deliveries from Amazon marketplace sellers more promptly than from Amazon itself.

I am on Amazon Prime, so everything ships in two days for stuff that qualifies.

However, when you choose First Class, that is the Post, so there is a variation on that time for delivery of 2 to 3 days, Priority Mail may be faster, but it is a 2 to 3 day range too.

Whenever I get something from Amazon and it does not go two day, I just don't even worry about when it will show up as it can take 3 days to 3 weeks. For example, a coffee maker, http://www.technivorm.com/ that I ordered from them is going be here next week, but the estimate puts the deliver date starting tomorrow and it is still in New Jersey, 5 days away.

Depends on where and the postman.