My first experience with a salesperson attempting to sell me additional items while making a purchase was at Nordstrom when I was nine.
I had finally saved up enough allowance and dog-sitting money to buy a new pair of Guess jeans (yes with zippers). As I counted out my money at the counter, the woman asked me, "would you like some slouch socks or a scrunchie with these?"
Caught off guard by this new (to me) sales approach, I mumbled, "yes" before realizing I only had enough for the stone-wash jeans. The scrunchie and socks would have to wait.
As I grew older, I realized this was a common tactic of sales people and I even practiced it myself while working in the student store in high school ("would you like a soda with your Otis Spunkmeyer cookies") as well as when I worked at Abercromie and Fitch ("perhaps some perfume with your ripped jeans?")
Usually, the items offered make "go" with the original purchase. However, I have noticed lately this is not always the case. See the following incident below:
Today, I decided a nice vanilla ice cream cone would really hit the spot after walking my dog. I cruised in the drive-thru and placed my order via the screen and waited for my total.
Instead the voice replied, "would you like some oatmeal to go with that?" Oatmeal? really? Not only does oatmeal NOT go with ice cream, but it was also three in the afternoon. Hardly oatmeal time.
"No thanks," I replied.
But the voice did not give up on me yet..." Would you like to try a large fry or a large soda with that?" Now I was just getting annoyed. If I wanted a large soda or large fries I would have ordered them. And again, neither really compliments a small ice cream cone.
Pulling up to the window, I retrieved my ice cream cone (sans oatmeal, fries, or a large soda) and drove off.
I did not go for the sales pitch, but my guess is many people do. My only objective is: if you are going to try to tag on additional purchases at least make sure they compliment the original.
Also, if I could go back to that day where I bought those Guess jeans, I wish I could have also purchased the slouch socks AND a scrunchie. Both of those go with the jeans much better than the oatmeal would have gone with my ice cream...