Seniority in the work place, it happens. What do I mean by this? Well lets say you just made friends with a co-worker at your new job, but you have only been at this 'new' job for less than a year, while your co-worker has been working at the same job seven years. And you and your co-worker aren't far off from each other in terms of how much you get paid per hour. You both ask for a raise, who is more likely to get it? The one working seven years or you? One would generally say the employee who has been there longer. Correct, generally speaking. But what if you feel that you are just as deserving or more deserving depending how well you both perform at work and the quality of work that is done; even how many hours you may clock during a regular work week. Now who is more likely to get said raise, you or them?
In my opinion how long one has been at a job should come last and 'used' only in extenuating circumstances. If you and said co-worker have the same job title, work almost the same amount of hours, you both are within $5.00 pay per hour of each other, and you both work just as hard. So you both, in theory, should have equal opportunity of getting a raise, though your boss may not out right say it, the deciding factor for them is not how well you both perform at the job, it's who has seniority. If it isn't a raise it may be other perks, such as extra vacation time, while if you may want extra days off, you'll need to jump through more hoops, just because one has been there longer than you have. Is it unfair, yes it is.
That happened to me once. I had this job in a restaurant throughout high school. I though for sure I would get a raise in pay over my co-worker who had only been there six more months than me. I instead got fired in January of 2007 after I had been working hard there at the same job for almost four years, and my co-worker (also a dishwasher, much like myself) got to keep his job, and got a raise. He, in my opinion, did not deserve it, because of how much he slacked when he was supposed to be working and how many times he would show up and leave early for his shift. Things like that are unfair to those of us who genuinely work hard and give their job their all and don't get the 'reward,' because someone else got it just for the sheer and utter fact that the other person has been working there longer than you have.