If you have a 2/3 majority to decide the rules, you can pretty much do anything
This.
With less than 1/3 solid supporters there is little we can do to change the Platform or gain concessions from the non-Paul nominee.
Having between 1/3 and 1/2 the votes means that, if we coordinate, we can stop the process and force compromises in order for the majority to be able to continue with whatever business they are trying to conduct.
Over 1/2 but less than 2/3rds then we have a majority and can substantially influence the nomination and largely control the Party Platform.
2/3rds or more and we can fire all the establishment leaders, elect our own, re-write the rules, and generally have our way with the entire process.
So even if worse comes to worse and Romney gets the nomination on the first vote if Paul has 1/3 or more of the delegates he will be able to wring concessions out of Romney and the GOP, real concessions that the party would include in it's platform and possibly getting control over the VP or major cabinet appointments.
This won't mean much to the avid anti-Republican types who think Ron should abandon the party and run independent, but it's a hell of a lot more control than the pro-liberty people have had in decades and should not be squandered.