New client opportunities for large SI/Consulting forms will typically come from a formal tender process - especially when you're talking multi-million £/$ engagements - as these need to be transparent and seen as a competitive bid. There's usually a formal RFI (Request for Information), followed by an RFP (Request for Proposal) from clients. Assuming you get through elimination process, there will a formal pitch presentation after which the client will select a firm.For existing clients it's easier to tack on new opportunities under an existing master agreement, and all it takes is having good relations. Alternatively once you've done some work for them they might add you to their preferred supplier list, which means any new work will be offered to a select group on that list.I have seen some work come through from alumni, conferences, networks etc, but from my experience these are far and few between. It might be different in some of the niche MC houses so will let others comment.Terms of engagement, Letters of engagement, Statement of work, etc. are all fairly similar but have slight nuances depending on what state of negotiations you're in and whether a formal contract is in place.
