Small advantages bounce around?

Actually, as your total advantage is growing consistently, even more slowly than linearly, you should be able to say that small advantages accumulate. And similarly, they escalate as long as the growth is accelerating. In calculus terms, small advantages accumulate while the derivative remains positive, and they (also) escalate while both first and second derivatives remain positive. So now I think that my original usage suggestion is too restrictive.

Of course, if you really have a precise mathematical idea about growth, then you could just say that! So don't read too much into anything that I say.