Re: How many times?
At best, Amazon for example, it's about extracting your money as quickly and efficiently as possible.
Amazon is on my list for the worst-performing site I use, and getting slower every year. I'm always waiting ages for javascript to load until I can open a larger image. It's so bad I went from always shopping at Amazon, to now starting my shopping at eBay and only with hard to find or more expensive items will I compare what's available on Amazon.
And once I've decided to buy, what does Amazon do? Stop the process cold to try and force me to sign up for a Prime subscription, or else hunt for the one square centimeter of space on the screen I can click on to place my order. And only then do I get the privilege of changing it from premium shipping back to FREE.
The kitchen sink website design of Amazon makes it about the worst looking on the modern internet, too.