My Pros all say "seemed" in them, because I got hired several months ago and never actually got to start work. I was extended an offer in November and was promised by my new manager that they would start me sometime around January/February although the "official start date" was March. When March rolled around and I inquired about why I didn't have a set start date yet, I was informed that my start date was being deferred to sometime between July and September because client acquisition was slow for the team that I was supposed to be working on. I talked to everyone I possibly could to get this changed because, as a fresh college grad, I didn't have many resources to survive on and I was counting on this new job (which I let them know numerous times). I tried to change teams, requested my signing bonus early, tried to work with Robert Half for some temporary work, but Protiviti wouldn't budge and Robert Half didn't work out. I eventually ended up finding another job.
BEFORE YOU ACCEPT YOUR FULL-TIME EMPLOYMENT OFFER, I URGE YOU TO GET YOUR START DATE IN WRITING.
Deferring my start date had a significant impact on my life and I would really hate for that to happen to someone else.
Aside from that, I would advise taking what Protiviti employees say about booming client acquisition with a grain of salt, especially since they get nice big referral bonuses.