Me : Who is the BEST teacher? 

Myself : The one who can be with you 24X7 and you can ask anything to him 

Me : But what about the expertise? 

Myself : Yes that is of course important but not more important than the access and bonding.

People have been at the receiving end till now in training and development but with technology in terms of online learning and social forums in picture, it is possible to build a group of trainers inside the organisation. There are multiple benefits of having trainers from inside the organisation in terms of cost savings, 24×7 access to trainers and bonding between employees. Of course not everything can be insourced, but with help of technology you can surely think of insourcing as a viable option.