I would say over 90% of advertisers that use PPC use it to benefit their own business. They use it to bring traffic to a landing page that might generate conversions for their business. There are all sorts of reasons why advertisers advertise but the main being to benefit themselves. However, a few advertisers decided that instead of a PPC campaign benefiting themselves, it should hinder someone else. This came across as an interesting topic when I first learnt about it and it still is. Instead of benefiting, hinder your competitors. 
 
If you still don’t understand what I’m going on about please read on. Let’s take an example. You are a car manufacturer and your main competitor is Ford. You could take two different approaches through PPC to gain you primarily more sales:

• Run a campaign advertising your own cars – This is the typical ad campaign where your core objective is to benefit yourself. Advertisers do this type of advertising campaign the vast majority of the time.
• Run a campaign advertising your competitor’s cars – This is where you advertise your competitors in such a way through PPC you give them bad brand image.

From this let’s take two text adverts. Advert 1 will show you a normal advert:
Low Cost Fuel Efficient Cars
Buy from the most recognised
car name in the world!
www.amazingcars.com
 
The next advert is attempts to reduce the brand image of Ford:
Ford Cars for Sale
Up to 75% off cars that are
only one year old.
www.fordusedcars.com
 
The second advert has a hidden message in in. By claiming that Ford cars depreciate at a staggering 75% in just a year, this will help turn people off Ford if they were planning to resell their car. This will reduce market share from Ford’s perspective freeing up market space for the car manufacturer to fill.
 

Why Would You Not Want To Advertise Yourself?

It is a question that many advertisers including yourself may be asking. Why should I produce a brand image on my competitors rather than just advertising myself? Sabotaging a competitors PR may prove decisive in increasing your sales. However, if you want to use this method of advertising, you need to know a few things:

• Only use facts – you can’t just make up a load of rubbish about your competition as you will get in trouble.
• Try to become an opportunity cost – an opportunity cost is basically the ‘next best thing’ or ‘second best’. Once advertisers have been drawn away from the market leader, you need to make sure you are there to pick up the scraps at second best.
• Don’t make it obvious! – You can’t just say ‘Don’t buy a Ford as they are more expensive than us’. That won’t get you far at all. The aim is to send messages to the advert reader making it not at all noticeable to the reader what you are doing to your competition.

Hope this helps!