Every title helps

I see that Tesco boss, Sir Terry Leahy, has become the latest businessman to accept an Honorary Degree - a pointless bauble that's either a) the height of vanity to accept or b) a shameless begging letter if you dole them out.
The retailer has been "honoured" by the University of Hertfordshire (Hatfield Poly as was) with a gong he can now add to the other honorary award he has from Cranfield University (formerly Cranfield Institute of Technology) - plus the 2:1 in management science he obtained from UMIST in 1977 when he actually had to pass a couple of exams.
This latest degree means Sir Terry joins a growing club of business knights who are rather partial to collecting these trinkets. Among their number is the great Sir Derek Wanless - who loves publicising awards from former Polytechnics yet doesn't like talking much about his time as head of Northern Rock's risk committee.
Why do these people do it?