Reng8d,
Thank you for your post. The offer you received was to renew early and add an additional 3 months to the 12 month paid renewal. This offer would extend out from your current August expiration date. So if your current expiration date is 8/31/15, taking advantage of this offer would make your membership good until 11/30/16. You do not lose any time on your membership by renewing early.
As for the different levels of membership, you can find information on these in our FAQ section of the website at the link below:
http://www.goodsamclub.com/FAQ.aspx
I hope this clears things up. Please let me know if you have any further questions.
Thank you for your membership,
Nate K.
Marcus' Rapid Response Team