Figure out who the target audience of the show is. If it's teens then the marketing and advertising techniques may be different than if it's aimed at working men aged 35 to 50. Also consider the advertising budget. If you have a small budget you may not be able to afford TV commercial advertising and need to go viral with your message. Also look at the distribution range. For international shows you need to reach people all around the world so while you may choose commercial advertising you will need to make a different commercial for each section of the world because the humor, phrases of speech, situations and language all vary. International advertising is widely done via the Internet because it's the most global medium and can spread the most rapidly through the communication of others. A national show benefits most from commercial and print advertising because it can target specific areas and cater to their general demographic. Local shows benefit from print advertising because billboards, flyers and other promotional materials can be seen and distributed personally to the potential consumer. The one-on-one interaction is powerful.
Commercials are the most common and traditional way to advertise a television show because you get to reach your general audience (those who watch television and preferably on your network or station) and show the television show for what it is in the correct format. Just like previews for movies the commercial is the gold standard for television shows. This is one of the best forms of advertising because the television show is a visual medium and you are representing it as the medium it is. Also our society and culture in general are visually oriented.
Print ads include magazine ads, billboards, and even flyers or posters. These are visual representations of the show which often include photos of the main cast, the logo or a conceptual artistic design to evoke an emotion or symbolize the television show. These have to be visually stimulating so someone will stop and look at it, then read the small text that gives the information on when and where it shows as well as the tagline or motto which gives the viewer a taste of what the show is all about. Like commercials, print ads are visual and our society thrives on visual stimulation.
Spoofs, outtakes, behind the scenes clips and short funny videos made about the show or with the cast are great ways to make videos for the web. These can be emailed to people, posted on Youtube and other video sites and put on websites to bring attention to the show. The more outrageous, funny, scary or unusual the video the more likely it is to be passed on, recommended and get press coverage of its own which will further help spread your message and push the advertising campaign along.
Hire people to post blogs, create fan websites and talk about the show in forums and online communities. Create a web presence. The Internet is very powerful and more and more people are using it to promote everything from homemade products to billion dollar business ventures. There is a lot of power and influence in having a grassroots campaign of ordinary people talking about the show because it creates a true buzz and interest that cannot be replicated through other advertising means.