One of the $9$ account management mistakes described by The Canadian Professional Sales Association is "majoring on the minors". This means:

Multiple Choice

Failing to provide an immediate solution to a customer$$s problem often results in losing them to the competition.

Making the high$-$volume clients more important than the smaller accounts results in losing several small accounts worth more than one single large account.

Having excessive focus on the high profit items in your product line up means that not enough attention is given to entire product offering and the business becomes a "one$-$hit$-$wonder".

It is easy to get caught up in a transaction and forget the relationship. Haggling over money can cause you to lose a client that is worth a lot more in the long run.