Dear Aditi,
Appreciate for Good Question,
Joining bonus can be given for several reason some times to bring the candidate from different location.
Joining bonus is a sum of money paid to a new employee by a company as an incentive to join that company. They are often given as a way of making a Compensation package more attractive to the employee.
Companies are offering joining bonus as demand for skilled workforce is high, at times there are crucial positions to be filled for which companies cannot wait to get people on board,"
The main reasons for offering joining bonus is to ensure that the company gets the right talent at the right time
Joining bonuses is estimated to be in the range of 10 to 20 per cent of the employee's Cost to Company (CTC).
The trend of joining bonus is more seen in sectors such as BFSI (Banking, Financial Services and Insurance), IT, Services, Power, Energy and Infrastructure.
I have noticed that several companies offer joining bonus to a prospective employee to join early (or shall I say "immediately").
Hope this have clear your doubt.