Have you ever searched for products on the Internet and then later had banner ads showing similar products everywhere you go? This type of advertising is called re-marketing and it is one of the features that Google offers through its Adwords product.
How do external websites find out about my search history?
Google tracks search history and browsing habits all over the internet by serving and analyzing cookies. Any website that uses Google features will also allow Google to track users using cookies to add to their database of shopping habits and interests.
Basically, if you leave an online shop, they can forever track your browser across the internet and serve you ads to entice a sale. Since Youtube is a part of Google, you may even have ads served while watching your favorite videos.
Ads are typically targeted narrowly towards visitors of certain products. Serving up generic ads of any category to previous website visitors is not quite the same thing as targeting product categories. If you visit Walmart for bike parts, you probably wouldn't be swayed by ads in the produce section.
Even Purchasers Are Persued!
Remarkably, customers that have purchased items before are sought after by advertisers even more aggressively. The logic behind this is that customers that were willingto spend money online would be willing to do so again and again. This is not far from the truth as it is a statistically sound theory.
Staying Connected With Your Target Audience
If you own your online store, you will want to keep your customers together as a part of a community. Even if purchasers do not click on your banner ads, the presence of your brand name will keep your brand in the back of their minds.
The Down Side: It's More Expensive
Obviously, Google will want to charge more for re-marketing ads as they are likely to lead towards purchases. Fortunately, it is still much more expensive than pay-per-click costs in extremely competitive niches. This is why re-marketing is a great method that for smaller niches rather than mass marketing your product.