Customer migration- best practices
I'm in the process of moving my site to Shopify from an Amazon web store. I used Shopify's tool to import my products and customers.
So I now have everyone who purchased at my previous Amazon store in Shopify but I'm assuming I just have email, name, address data- no passwords. My question is how I should handle this moving forward. Should I-
#1. Delete the accounts so everyone is starting fresh? I have no historical data imported that would be lost and I can export the data to a .csv file so I don't loose it. Customers would be instructed to create a new account when they first turn up.
#2. Keep the data and trust that customers will be willing to request a temporary password from the new Shopify site. I'm assuming that is how things work- must say I haven't tested it yet.
What I'm concerned with is that people will try to create an account using their email and it won't work because there will be exisiting accounts in the system already leading to much confusion.
So, what is considered best practice in this situation?