koolguy,
There are many tools in the marketing toolbox. One way to get your product out to potential clients is to advertise your expertise in magazines read by potential clients. You wouldn't advertise in home and garden unless your electronic devices aid in those two areas.
When thinking about your marketing efforts, you are investing
money in those advertisements and expect to recoup that money via sales. If you spend 100 per month and get 10 back in business, you'd have to decide if losing 90 a month is good or bad.
I hate cold calling, According to one blog, the rate of return is 0.3 percent.
http://blog.simplesalestracking.com/2013/03/21/does-cold-calling-still-work/
Extrapolating that out, you would need to generate a contact list of 3333 to get 1 client. Explore internet marketing and pay attention to the rate of return. You could buy a million email addresses and "hope" you get your investment back via sales. I have no idea on the rate of return for those who purchase email addresses.
Search engines track your explorations and present custom advertising based on your surfing. Google adwords might be worthwhile. Word of Mouth is generally considered the best rate of return.
To paraphrase May V Smith, "the only place success comes before work is in the dictionary." All marketing is work.
Do a youtube lookup of gabe and garrett. They have a successful business because of their youtube followers, as does the ever popular Dave Jones, EEVBlog, is another successful business because of his youtube followers.
http://www.youtube.com/watch?feature=player_detailpage&v=XwAVYbV5rLk
Find your niche. Exploit it.