Ok, from SS2 and Ray Zee's book I've understood that when you have 3 lo cards at 7cs 8b, the idea is to just call the bring-in and not raise because I more often than not will split and I want to keep 3rd party donations in the pot. Right? Perhaps raise if you have really good 3 lo cards, like 3 to a str8 flush, but then again, you will potentially scoop so why raise even then and lose the long shot chasers who will fall in love with their draw on 4th and pay until the river.

This usually seems to work out as expected (i.e. folks just calling with 3lo) on lower limit (.5/1 - 2/4) 7cs8b tables. But on higher limit, like 3/6 and 5/10, some people seem to raise quite often with just 3 lo cards.

Why is this? Why do they want to chase the donators away from the pot? Or is there some other more in-depth reasoning behind this that I just don't get?