In this post, Paul Graham warns the founders against premature discussions with Corporate Development. They have no other ambition than to discuss the buyout of your company.
Beyond the flattery and hopes generated by a meeting with the Corp Dev of a large company, the founders should simply ask themselves the question: "Do we want to sell now?".
If the answer is no, they simply have to decline, according to Graham. In this case, it is useless to enter into discussions with professionals whose performance is measured on their ability to buy you for the lowest possible price.
Startups should only talk to corp dev when they're either doing really well or really badly. The danger is to companies in the middle. Particularly to young companies that are growing fast, but haven't been doing it for long enough to have grown big yet. It's usually a mistake for a promising company less than a year old even to talk to corp dev.