The headline makes the content look far more devious than it is. There are two things you should know about price discrimination and online shopping:
1) If you get the cheapest price online, then you shouldn't worry about price discrimination.
2) Price discrimination often isn't price discrimination at all. Pay more for shoes after a certain time? Perhaps the people that shop after 7PM are more likely to take advantage of the customer service and return policies, so they are actually paying for the shoes and customer service. Price tag different if you live in the suburbs? Perhaps the people who live in the suburbs are harder to deliver to, so the delivery cost is built into the price.
Price discrimination by definition is two identical products offered at different prices. If on the other hand you can find a difference in two seemingly identical products then it isn't pure price discrimination.
And seemingly different price differences have been around long before the internet. Example: coupons for the grocery store. Airlines are just an extreme example of this.