BeauDez wrote:The two new cards will cut my AAoA from 5.5 years to 2.75. How much of a hit should I expect from this and how long does it typically take, paying balances on time and in full on all accounts, before that hit is erased?
AAoA is pretty straightforward. Paying on time and in full isn't relevant to AAoA. AAoA is just total age of all accounts / number of accounts. The only way to build AAoA is over time. In your case, with an AAoA of 2.75 and 4 accounts you have 11 years and 4 accounts or 132 months (AAoA math is generally easier with months) and 4 accounts. That's an average of 33 months per account. In one month you'll have 136 months and 4 accounts or an average of 34 months per account.
Paying on time helps with Payment History. Paying in full and credit lines aren't really as important for scoring as is Revolving Utilization (balance[s] / limit[s]) which factors into Amount Owed.
The standard FICO factors and their typical weights are:http://www.myfico.com/crediteducation/w ... score.aspx
It's not just about the impact to AAoA and the impact of the hard pulls with new accounts. Having new accounts on your reports can be a concern for creditors depending on the state of one's credit profile. Since you're really just starting off and have a thin profile the amount of new accounts that your profile will support will be very low. Sticking to the rate you mentioned is probably advisable until your profile thickens and ages.
BeauDez wrote:If they repeat Amazon in Q4
No if to it. The 2016 calendar is posted:https://www.discover.com/credit-cards/c ... endar.html
BeauDez wrote:My credit score has been going up and was 776 as of August 1st.
You don't have just one score. There are many scoring models used by creditors in their decisions. For most models you have a score with each of the 3 major CRA's. For the FICO 8 model, for example, you'll have a score with TransUnion, a score with Experian and a score with Equifax. Make sure you're not overlooking the other 2 major CRA's. Also keep in mind that accounts where one is an AU may not be considered in all cases with all models and creditors.
BeauDez wrote:The question is, if I get that card as well during this window, will a third new card, which would lower the AAoA to 2.2 years make much of a difference in the total short term hit on my credit score? Also, does store credit have the same effect on my overall score as a Visa/MC/ etc...?
A revolving account is a revolving account. It doesn't matter if it's a VIsa, MasterCard, store card, line of credit, etc.
It's never just about the change itself but one's credit profile as well. As I said, your profile is new and thin. Adding a new account is going to have a bigger impact -- not just because of AAoA and the hard pull but from having new accounts as well -- for you than it would for someone with a thicker, established profile. While you might be limited to adding X accounts, another person could possibly add many more accounts without the seeing the same impact.
It's entirely possible that you could sign up for the Prime Store Card and not see any adverse impact. I really can't guarantee things one way or another. However, with what you've presented I'd recommend cooling your jets and letting your new accounts age. Building and rebuilding credit is a long, slow process and far too many look for quick and easy fixes and get too excited with approvals and start applying left and right for credit without putting much thought into the matter. You're off to a good start. Stick with it. Just work towards paying all statement balances in full and don't spend what you don't have.