Bidder conferences can have a negative impact on the project if the project manager does NOT remember to make sure :
a) All the questions and answers are put in writing and sent to all sellers
b) All sellers get answers to their questions only
c) To hold separate meetings with each bidder to ensure you receive proprietary data.
d) There is room in the meeting for all sellers
Remember that the procurement process is more formal and thus requires more formal processes. Ensuring all bidders receive the same information in writing eliminates the problem of bias in presenting the opportunity.