This data item is calculated as sum of strong buy / buy recommendations divided by the total number of recommendations for the stock. Stock brokers regularly put out their recommendations about particular stocks. These recommendations could be either strong buy, buy, hold, sell or strong sell. Each broker covering the stock will usually have one of these recommendations for that stock.
Suppose 10 brokers are covering Maruti Suzuki, 3 of them have strong buy recommendation, 2 have buy recommendation, 1 has hold and the rest have sell recommendation. Percentage buy recommendation is calculated as (3+2) / 10 = 50% .
Number above 50% is considered to be good because more number of brokers have strong buy / buy recommendation for the stock compared to hold or sell. Closer the number is to 100% the better, indicating higher confidence in the prospects of the stock.