Min bet at my level reprsents middle or lower pair. If flop comes KK3 a min bet is supposed to say I have a pair of 3s. Of course, it is just as likely they have a K so poeople fold unless they have a K. hehe.
If flop comes 47T, a min bet is usualy saying I have a 4 or a 7 and that is fairly likely.
I don't bet like that but lots of people at my level do.