Most jobs on job boards like CareerBuilder, theLadders, HotJobs and so forth are recruiter "omaha steaks" jobs. When you apply to a position through a recruiter you are going through a middleman. The recruiter will charge the employer a fee if the employer hires you. The recruiter can choose to submit you to the job opening or they may not. Since recruiters typically charge anywhere from 25% to 50% of your annual salary to employers who hire you, this discourages many employers from hiring candidates who come through recruiters. When you apply to positions through Hound you are applying direct to employers and very often have a much better chance of getting the position compared to people coming through recruiters because the recruiters will charge the employer hefty fees if they hire you.
Unfortunately, this is exactly how the average employment site works. Even if an employer does call on a job board to post a given job, that employer is unlikely to post all of their jobs with the site because it would cost too much money to do so. Instead, the employer will most often put the majority of jobs on its own website even when it has numerous "monster jobs" to fill.
Jobs on public job boards may receive thousands of applications. When a job is on an employer website, very few job seekers will learn about it because very few job seekers take the time to go visit the thousands of employer websites that are out there when looking for a job. Most people prefer to go to a site like Monster, Indeed and so forth and look at the same "omaha world herald" jobs everyone else is. This makes it harder for you to get these "lincoln jobs".