Amazon FBA (PL) Buy box Reflection

What is the buy box for FBA PL mostly connected with? 

In FBA (PL) Buy box is the Indicator to check your Account health and your Brand's Market Shares. Now, let me explain to you here how your Account health directly correlated with your Market Brand share. 

When you have higher returns/defect rates or any issue with your account health that results in losing your account health, Amazon logarithmic will gradually affect your visibility, BSR, and chances of losing the ad bidding benchmark for your items that have autonomously low visibility. Hence, we can derive from the above situation that low visibility means low conversation, which would affect your buy box in the event of a drop.

However, the market brand share is the combination of your position and conversation rate in specific brand and category keywords.
In the meantime, it would be obvious that by losing the Market brand share, you are losing potential sales with multiple factors which would be due to account health, brand awareness and Product Visibility.
 

Now, we can conclude that Account health and Market Brand Share are directly correlated. In both cases, they serve as an indicator to determine whether your buy box is over or undervalued.
 

Losing Buy Box Determination would rely on your efforts to determine whether your account's health is suffering or your market share is declining...!!!