Microsoft ESPP

Hi Folks, There is ESPP in Microsoft, that lets you set aside upto 15% of the base salary, and buy MS stocks at 10% discount every quarter. What is the net profit/loss after tax, if such stocks are immediately sold after crediting to the account? I have read somewhere that 10% of the amount is initially taxable as Tax prequisite. What else is deducted? What stops everyone from investing in this, and selling immediately (other than having to wait for 3 months) Thank you! Yoe: 10 TC: 80 #software #microsoftindia #microsoft #espp #salary