When you get that job offer, you may be feeling pretty confident about your prospects. It's obvious that the company wants you. Otherwise, why would they make you an offer in the first place? If the salary wasn't what you'd hoped and you try to negotiate, there's always the risk that the whole thing could blow up in your face. In the worst-case scenario, the employer withdraws the offer and you're back to the drawing board. While salary might have been a factor, a number of other things could have come into play to force the employer's hand.
First, reflect on your behavior during the salary negotiation process. If you acted cocky, disrespectful or downright rude as you asked the employer for more money, it might have rubbed him the wrong way. You may also have asked for way too much and signaled to the employer that you'd be something of a diva if hired. The best way to combat that is to know the salary range for people in similar careers, using data from the Bureau of Labor Statistics or other job postings.
When you're entering negotiations about salary, you're selling yourself. Like any other customer, the company wants to know what value it will get from hiring you, or what special skills, talents or connections you'll bring to the table. When you presented your counter-offer, ask yourself whether you showed the employer any additional value you'd bring to the company. The company already learned about your education and experience from your resume, but you needed to bring even more during the negotiation process. You should have talked about how many customers you'd bring in, how you'd come with a list of clients, how you'd save the company money or some other factor that would have made it impossible to say no.
In some cases, the employer may not have done all the homework before offering the position to you the first time. The hiring manager may have neglected to call your references until very late in the game, and found out something that turned out to be a deal-breaker. In other cases, you may have included a reference who the employer couldn't get a hold of -- another red flag for the employer. Another potential problem: the employer might have found out that you've recently interviewed with a competitor. Some employers enjoy that game, others hate it.
If you find yourself in the position of going back to the drawing board and starting your job search all over, you should have learned a few things in the process. First, don't give your notice at your current job until you're 100 percent sure you got the other job. If need be, ask for a pre-employment contract stating the terms of your employment and what the new employer will have to do should he renege on his promise. Second, always tread carefully in all negotiations. If you're not sure why the employer took back the offer, it doesn't hurt to ask. Some hiring managers may be more than willing to share how you screwed up; others may not give you the time of day.