Conversion and Retention Ratios

Okay folks. I am getting conflicting stories on how retention and conversion ratios are calculated. If I want to tell affiliates that our site converts at a certain ratio, what is the industry standard for calculating. We have some mega sites that are only 1:2000 but lots of mid size sites that are 1:70 and a handful of little traffic blogs that convert at 1:25 (with 4 or 5 sales a week for each of them) How should I calculate the average conversion ratio? Is it a median or average?

Ditto for rentention. Is it for two, three, four or six months? Different people tell me different things.

Thanks much. Glad to be back at work after a difficult weekend to be sure!

There is some good info in this thread about calculating your retention ratios...

http://forums.gaywidewebmasters.com/...ad.php?t=14833

Conversions - How much traffic needs to be sent to make the sale.

Retention - How long a member stays in the site once they have joined.

Regards,

Lee

Very handy. Thanks!