Question about IP profile increases

[#1]

Just wondering about these IP profiles, I've read here http://www.kitz.co.uk/adsl/IPprofile.htm#IP_profile and been told that if you hold a stable connection for a full 72 hours (3 days) that the IP profile SHOULD increase but does this mean you have to wait 72 hours for each and every profile increase? For example,
For an increase from 4544 kbps to a 5088 kbps (IP profile of 4000 kbps) it will take 72 hours?
Then for every increase after that it will take 72 hours each and every time?
From                              To
5120 kbps                      5664 kbps (IP profile 4500) Up to 4.5 Mbps
5696 kbps                      6208 kbps (IP profile 5000) Up to 5.0 Mbps
6240 kbps                     6784 kbps (IP profile 5500) Up to 5.5 Mbps
6816 kbps                     7360 kbps (IP profile 6000) Up to 6.0 Mbps
7392 kbps                     7936 kbps (IP profile 6500) Up to 6.5 Mbps
7968 kbps                     8096 kbps (IP profile 7000) Up to 7.0 Mbps
8128 kbps                     9087 kbps (IP profile 7500) Up to 7.15 Mbps

So if it does take 72 hours for each increase, to get to the max speed a line can handle, let's say 7.15 Mbps for sake of argument it would take 21 days!?
Or can big speed increases happen all of a sudden say from 5.5 Mbps (IP profile 5500) to 7.0 Mbps (IP profile 7000) or doesn't it work like that?

[#2]

If you carried on reading http://www.kitz.co.uk/adsl/IPprofile.htm#IPprofile_increase_time ;
Depending the increase it can range from 4 to 120 hours. I know that the general advice is 3 days (72 hours) but I have had my profile increased in less than 6 hours.

[#3]

It typically takes around 72 hours for a change to happen, but then it will be to the appropriate speed, so for example on standard ADSL 1 you could go straight from 135kbps to 7150kbps.
In fact, if the difference is large it should take a lot less than the 72 hours.