"Why haven't you received any offers so far?"
"What offers have you received so far?"
This is another type of question that most interviewers will not ask. But just in case, I'll provide an example. For the question asking what offers have you received so far, you can simply list the ones you have received without details. For example, "I received offers from Boeing and InfoSpace."
But if they ask you why haven't you received any offers, then your answer will depend on if you have an offer or not. If you do, then you can politely correct them by saying, "Actually, I received an offer from Intel. But I didn't respond with my answer yet because this company is my first choice."
If you do not have any offers, then you can say something like this example."I just started interviewing this past week, so it's a little too early to tell.""I recently started looking for a job, but I'm hoping that I'll receive offers soon.""I received one offer from a smaller company, but I want to see what else is out there. I like what this company has to offer so I'm hoping everything turns out well today.""I've only interviewed with two other companies so far and I have a second interview with one of them. It's too early to tell if I'll be receiving any offers right now, but I'm confident that I will get a couple."
This answer is suggesting that you are actively interviewing. Mentioning a second interview with another company also shows that you passed the first interview stage. You are not admitting to any fault by not receiving any offers, but simply saying it is too early because you haven't been searching for a job that long.
If you have been looking for a job for a long time, then you will not be able to use an answer like I just showed. Instead, you might have to be honest and try to put the blame somewhere else. More likely you will not receive this answer, but just in case, here is one more example. This example admits directly to not receiving any offers but shows diligence and shows that this person doesn't give up."Most of the jobs I have been applying for require more experience than I have. Also, because the job market is rough right now the competition has been pretty tough. But I plan on self studying continually and I know through my diligence that I will get a job soon."