This has become common for us when hiring in India where the offer to start dates are measured in weeks to a month or two.
The candidate will accept the offer, keep interviewing other places then, shortly before the start date(usually as we begin getting hardware shipped to an office for pickup, assign mentors), they pick the job that pays best/more prestige, etc.
We had one case where the person worked with us for one week then quit because they got a better offer after starting.
Probably works out well for them, so I can see the reason why.
My manager moans about this all the time. I also side with the candidate. If they get more money or prestige, good for them. What my manager refuses to do: Call them up and ask what it takes to stay? He knows what the answer will be most of the time: money or title. Then he moans about "over inflated expectations". Awful. I point out time and time again: If they are getting better from another place, then we need to pay better. If you think too high, then stop hiring in the location.
The candidate will accept the offer, keep interviewing other places then, shortly before the start date(usually as we begin getting hardware shipped to an office for pickup, assign mentors), they pick the job that pays best/more prestige, etc.
We had one case where the person worked with us for one week then quit because they got a better offer after starting.
Probably works out well for them, so I can see the reason why.