When might goodwill increase?

I'm a little confused by M&I's answer to this question, which is:
1. during an acquisition because goodwill is a "plug" for the purchase price, or
2. when a company acquires another company but pays more than what its assets are worth

My confusion: Aren't these two answers essentially the same thing? If you're acquiring a company and your goodwill goes up, then isn't it a given that you're paying more than what the assets are worth? Maybe I'm missing something..

Thanks in advance