My approach to this is very different. Instead of writing articles and distributing them out to get links, I publish all of my content on my own site. This makes my site the link magnet instead of creating other sites that will compete with me.
If your method of getting links is to publish content on other sites then you must sustain that effort perpetually to keep your link count growing. However, if you publish all of the content on your site then your site grows and grows in mass and as it grows there are more link targets and the velocity of your link acquisition grows over time with the same level of effort from you.
There are two risks with this method. 1) it has a very slow start, and 2) you must be able to produce linkworthy content. If you can't you will fail, but the better you are at producing that type of content you will have velocity and something more important... acceleration.
Finally, although there are some good PR firms out there, many of them are nothing more than spammers who wear suits to work. Be careful if you go that route.