in my experience it doesn't matter at all... in fact I prefer to start out as professional, but it's all about the volume that you sell and how you do business in general.
And i start up as a Pro merchant, you cánt downgrade it to individual account. Atleast happen to me
You automatically go back to individual when you decide not to pay the $40. I opened an account as pro, didn't use it for 5 months.. then once I did I had to upgrade to pro again and activate the $40 charge per month.
and when you go pro (after selling for a while), they'll take a closer look at the account. I've lost 2 accts this way.
Absolute rubbish, they look at all accounts and all metrics. You will have lost your accounts with poor metrics. Look at your metrics and business and don't pass the blame onto amazon.