Im on page 2-3 for moderate difficulty keywords (35-40 KC on LongTailPro) What a decent sized PBN to try and reach the front page? I know it REALLY depends on metrics, but I'm just looking for a ballpark. From what I've heard, 5 is too small. How about 30? 50? 100? At one point should I be able to stop and say: This PBN is good. If I'm still not ranking, I should look at other factors.