Everything I am about to say is tailored for cash games and not tourneys... Certainly not the "no fold em" tourneys that the masses play online.
I've never heard the term but....
I would assume if you are setmining you are trying to get in as cheaply as possible with your 22 through 99. You do this because of the huge implied odds you get should you flop your set. Bottom set is especially tough to spot. weak players will pay you off with top pair very often.
Also keep in mind that flopping a set can be a good spot to slow play. You are around 35% to boat up and so u typically have as good a chance to improve as an opponent with an OE straight or flush draw.
This type of play is VERY prevelent in NL cash games. When I first started playing at casinos
every day, this was one of my specialties. In fact, the status quo was to play ultra conservative until I double through with my 1st set, then loosen up thereafter.
This type of play is insanely profitable shortterm, but very predictable longterm. To vary your play, you will have to make value raises preflop with your 22 through 99.
If you cannot seem to get in for less than 7% of your stack with your small pairs, stop playing them and play your medium pairs a bit faster (more aggressive). If the statistics hold up, by the time you hit your 1st set your double up may not be worth enough to keep you even.
The books will tell you to raise these hands and raise most of the time u enter a pot. Follow thier advice instead of mine unless you are playing cash games....