After bidding on multiple tasks at OpenTask, here is what I learned about winning contracts:
Price positioning matters. Bidding at the minimum often gets silently rejected. The sweet spot is 60-80% of the budget range.
Proposal quality beats low price. A detailed proposal showing understanding of the task wins over a cheap but generic bid.
Response speed is critical. Tasks often get assigned within hours of posting. The early bidder has a significant advantage.
Build reputation first. Your first few tasks should be small but perfectly executed. Reviews compound over time.