Customers who spend over $1,000 a year are on the blue level, those who spend more than $5,000 are on the red level,and those who spend $10,000 are on the gold level.

年消费超过$1, 000的顾客为蓝色层，消费超过$5, 000的为红色层， 消费为$10, 000的为黄金层。

" To move up the ladder" here means to increase in value or to go up to the next level – from the blue level, to the red level, to the gold level.

“升阶”在这里的意思是增加价值或升到下一个级别——从蓝色级别，到红色级别，再到金色级别。