The times Google have commented on every update are long gone. Actually this is a positive thing, because with more than 600 updates a year, we would soon have nothing else to do but to check our pages and see if adjustments are necessary. However, there are updates that are

Without A / B tests today runs almost nothing. To always generate new traffic it is only possible if the conversion fits and the visitors also become customers, otherwise the money and the time for the effort could be used better. However, A / B tests are not always easy