Score increase from AU balance

[Anonymous]

I am an AU on DH's Walmart account.  In August, we used it at Sam's and a balance reported. My scores jumped 12 pts. I figured it was a coincidence. We paid it off my scores dropped 13 pts after it reported. That made me go hmmm.  A few weeks ago, we bought a couple tv's on the account.  Sure enough, my scores went up 12 points again.  I went back and looked at prior months and this has happened 3 times now so it is not a coincidence. 

My utilization reporting monthly is 1% via my discover card.  Why is this 2ND account reporting fluctuating my score in a positive manner so much? Could the minimal balance I let report actually be too low for "optimal scoring"?

[Anonymous]

There is no hard-set rule that says only one account can report for the best returns on credit score points. It seems to be common amongst members that the whole 1 card, less than 10% util works for most people, but everyone has different information in their profiles and this may be something that affects you positively and may affect the next person negatively I guess.