How long do affiliate cookies last?

[Self Made]

How long a cookie lasts before it expires would seem to be a big factor in how well affiliate programs convert. But I don't hear it talked about (I've heard more discussion of first/last cookie and cookie vs. bonus codes), and programs don't usually point out the info.

I just thought to check out a new affiliate program I'm using by looking at the cookies in Firefox (tools/options/privacy/show cookies). It appears their cookies only last 24 hours! Some other rooms on the same network last months-years.

Any experience/opinions on how this affects conversion, and why it isn't discussed more?

[Self Made]

I'm surprised this didn't attract any discussion, because it seems important to me. Out of curiosity I took a look at the top six US-friendly sites/networks to see how long their cookies lasted. One problem is that they have multiple cookies and I don't know how to tell which one is for referral tracking (though sometimes it's obvious, e.g. they call it refer or affiliate). So sometimes there's a range below. These are the big six:

Bodog: 9 months
Carbon one month
Cake: 3 months to 2 years.
UB: 17 days to 2 years.
Stars: 175 days to 27 1/2 years.
Full Tilt: one hour to 9 1/2 years.

For one network where the cookie length is obvious I've seen a range from 1 day to months/years.

[Ridge]

While this is a good issue, you also have to factor in which rooms have bonus codes which over ride cookies. Fortunes have been built on this concept.