Recently we decided to get rid of our old couch.
Not wanting to chuck it into the trash, we looked at ways to recycle it. After a bit of searching we found one place that advertised $40 to recycle it.
By the time we got through checkout that price ballooned to $100.
Even though on the product page they said they'd pick it up, it was for an extra fee that they didn't mention until deep in checkout right at the payment step.
If we didn't research the competitor costs ahead of time, we probably would have balked at such a huge hidden fee. As it was, it made the transaction feel a bit border-line.
This sort of surprise is why a lot of customers abandon their carts. They invest time into browsing your store, only to be confronted with a high shipping cost at checkout.
One option is the just give free shipping and raise product prices, but make you look more expensive than competitors (unless you eat the shipping costs yourself).
Another option is to clearly share your shipping rates in the store and on the page. Then the surprise is lessened, though you run the risk of people not seeing the rates at all.
It comes down to trust and disclosure.
Sneaking in charges like this couch recycler might work once per customer, but they aren't going to become a repeat customer or refer their friends.
It becomes a pure-transaction relationship.
One that a competitor can take away easily.
Going beyond simple attribution, Repeat Customer Insights lets you analyze and segment your customers by who first sent that customer your way.
This will let you find the best sources of long-term customers, not just anyone who orders.