I signed up for the Silver Plan just a little while ago. Here's the relevant part of the chat transcript (with personal information omitted

). The first paragraph is obviously "canned" information--that may contain all of the information that you want to know.
Gurjeet: I'd like to let you know about our new Silver Plan. It's only $14 (plus applicable tax) every 2 months, instead of being charged every single month. This is a Bi-monthly plan in which you get 1 credit on your billing date and you get to use all of the normal membership benefits during this time, which include the ability to exchange any book ordered within the last 12 months days, no questions asked. This plan has become a great alternative option for customers who enjoy the Audible experience but prefer extra time to finish a book.
08:48 AM PDT Me: okay. let me look this over. please give me a second.
08:48 AM PDT Gurjeet: Would you be interested in taking advantage of this plan?
08:49 AM PDT Me: so it's 1 credit every 2 months?
08:49 AM PDT Gurjeet: Yes!
08:49 AM PDT Me: about what percentage of the audioboks on your site are only 1 credit? rough figure is fine
08:51 AM PDT Gurjeet: [My name] . . . 1 credit is equivalent to 1 audiobook, which means you can purchase the most expensive audiobook in an Audible regardless of its price.
Just to confirm, do you know about Easy Exchange Audiobooks feature?
08:52 AM PDT Me: oh, okay, great. some companies have 2 tiers--1 credit and 2 credits. that's the reason that i asked.
yes, i know about the easy thing
08:52 AM PDT Gurjeet: Just to confirm, do you want to know about 2 credits per month plan or about Annual plans?
08:53 AM PDT Me: now what the computer wrote said all membership benefits (or something to that effect). does that include sales that a member can take advantage of.
no, the silver plan sounds just right.
08:54 AM PDT Gurjeet: Yes, in this plan, you will have access to all the membership benefits such as sales, 30 % off or other eligible promotion.
Hi-OO Silver!