The first rule is simple: Do not try to market to everyone at once.
Good digital public relations has to do with avoiding “spam” – this is a term that is defined by each individual. If you are annoying someone with your communications, then that communication is spam. The major social media sites are quite sensitive to each individual’s definition of spam. If you are reported by only a few people, your website can be completely taken out on the internal search engines of major social media sites such as Facebook and Twitter, and you can be completely blacklisted from the major search engines Google, Yahoo and Bing.
You can avoid this by keeping your communications personal. Just because you can market to all 7 billion people on the planet at once with an automated message does not mean that you should. Even the people that would have otherwise been interested in your product will view your content is spam and disassociate themselves from you.
Second, use comedy and the concept of the viral video.
The best public relations that any company could ever get for itself is a video that goes viral. Usually, viral videos are either incredibly funny or incredibly informational. The production value on these videos is usually quite high as well. This does not mean that you have to go out and purchase expensive equipment; it simply means that you have to have someone behind the editing boards that knows what they are doing. The hardware that you need in order to create a good video is under $1000 these days – do not let anyone tell you that creating something that the entire Internet can view as a professional video is out of your reach any point.
Third, you must be sure to keep your content up to date.