There's bqsically IMO two types of ads - marketing and sales.

Marketing ads are signalling, brand recognition, etc. You want the cool earbuds that everyone knows. You want to buy them from a big, reputable company with good r&d.

Sales is simpler - click on the ad and buy the product. It tends to be a bit sleasier - sales doesn't care as long as it makes a sale.

There's often a bit of tension between sales and marketing. A 50% ooff exploding offer can be good for sales in the short term, but can make the brand look cheap.