One thing to keep in mind also is that pushing back against this negotiation tactic is good, but sometimes people do just have to move fast. I had five interviews two Fridays ago, and I offered the second candidate the job - starting on Monday, 20% higher pay than she asked for in her resume, and interesting roles. But I had to know right away, because I had to know what to do with the next set of candidates.
Also worth noting is that she didn't have a job currently - her previous company pulled out of China, so there was no risk to her of joining. I was more careful when I recruited a woman who was working at the U.S. Embassy, which was a fantastic stable position with solid pay - I asked her to start here part time for a week or two to make sure there was a fit before quitting a very good job.
Anyways, point is, people want decisions fast for many reasons. Look to see if it's in your best interest to decide fast, and decide fast if so. If it's not, push back. Not all fast paces are petty bargaining moves though.