It is difficult to say. I am now good friends with a very influential person in the Manufacturing sector through an organised network. He actually writes government strategy for the sector. I have also made some excellent connections in some major automotive and Paper manufacturers in India, the head of freight for the Indian rail authority (the largest employer in the world!), the British Consul General for Canada, The Canadian High Commissioner to the UK, the Head of Trade finance in the Midlands for HSBC and many others who are at the top of their game in diverse sectors such as construction, telecoms, consultancy, banking, IT and retail.
In terms of connections that I have made for other people, I connected a telesales organisation to a customer that doubled their size within weeks, a number of customers to suppliers in India and China (with the added bonus of us carrying the freight..!) another customer to a friend of mine who is working to sell their product in UAE and many, many others.
A good connection takes time, but when you have made one it is vital to keep the relationship going through regular contact.