Some people are building scalable predictive bid management software which is based on complex mathematical algorithms.

Former Yahoo executive Ellen Siminoff has re-emerged as CEO of Efficient Frontier, which produces a paid-search management service that was launched Friday. The service lets paid search advertisers predict the performance of their keyword purchases on paid search networks such as Google's AdWords and Yahoo's Overture Services subsidiary. source

The Efficient Frontier site states that they are the only scalable bid management solution, although I bet Kevin Lee would beg to differ.

Other individuals are also quietly developing their own proprietary bid management solutions.

Automated real time feedback and adjustment is what makes bid management software extremely valuable. This is one market where software price will not be the determining factor in who is ultimately crowned king... quality and breadth of the features will.