srd.yahoo versus other yahoo's

Can not figure out the difference

[Rugles]

I see in my logs that I get Yahoo traffic from several sources. The one I am most concerned about is refers that look like this:

[srd.yahoo.com...] ... rest of string

I am now seeing a slight variation of the srd.yahoo string which looks like this:

[srd.yahoo.com...] ... rest of string

I have read here that the srd.yahoo is a click thru tracking string. But why do they not track every click instead of just a few?

What is this "testg" thing all about?

[JamesR]

testg might be a google thing. Have you compared the results between searches with and without it?

Tracking every click through may take too much resources for them and slow the system down too much. Tracking a few strings at key times may give them the data they are looking for.

[Rugles]

I figured the "goo" part was google.

The ones that have "testg" also have "goo".

I will run some tests later when I have time to find the refers in the logs again.

Your idea on click thru tracking is probably what is going on. They are just tracking a small sample.