Mutual funds SIP gives good returns in long term!

Hi friends I have observed that people who are invested in mutual funds on sip basis will get good returns in longterm. Sip means systematic investment plan, investing fixed amount monthly in mutual funds. I am from india, most of my friends and colleagues who are invested in sip are in good profit. Benefit of sip is we get more units in downtrend and after resuming uptrend we will be slowly recover our losses and profit will start. In long run markets always in uptrend and breaks its previous highs. But we have to wait patiently to get returns.