Yeah, I agree the word is affected by semantics and I'm probably not going to add anything new to this thread but I wanna type!
A referral can be "please give us a name we can call" or someone contacts us because "so and so told us you did good work and we'd like to hire you"
In any case a referral is basically a prospect you come in contact with primarily due to a third part who either recommended the prospect to you or you to the prospect.
We don't ask our customers for names but we frequently are told by our customers that 'Edna down the street wanted you to call and set up an appointment.'
Personally I hate making such calls because I feel I'm intruding. But, I have also learned that if my customer says Edna wants me to call, then I had better call because it reflects bad on my customer if I don't.
And even though we don't ask for names we do ask them to tell their friends and neighbors about us. That has paid pretty well too.
We did work for a young buck one year but we screwed up teh job by hitting a shed. We made good on it and ended up doing a huge job for his neighbor as a direct referral.
Two years later we did some work for another guy by the same name as the young buck. The following year we did work for a third guy by the same name and a second job for the second guy as well.
Turned out they were youngest brother, middle brother and father and had been referred right up the line.
Those 3 guys landed us at lease a dozen other jobs without advertising.
Can't beat that for referral based marketing.
Do it right, do it with excellence and always exceed your customer's expectations and there is no reason you cannot be overwhelmed with help from your customers.