Leads and bids are essentially different animals. Leads are all about the sales process and efforts - qualification, presentation, specification, follow up, quotation, commitment. Bids are all about meeting the specs and being the lowest bidder. As a result leads and bids are tracked differently in Opportunity Tracking.
Bids are a one time opportunity with specific products that have to meet certain specifications - product, packaging and shipping. There's not a lot of selling taking place for a bid. A municipality or state or school or hospital puts together a list of products that it needs and waits for the prices to come in. Other than creating specifications that may limit your competitors, for the most part the lowest bid wins. And while it's good to know what phase the bid is in, the close reasons are the most important - why you won or lost the bid. Once the bid is awarded the sales person has to wait until the next bid opportunity arises to get the business.
When tracking bids, management can sort and filter by the type, by manufacturer, by dollar volume, by competitor, by close date, and by close reason. This allows them to see and share results and trends with their manufacturers and customers.