Demand for advertising on Yahoo’s network was stronger than expected, which enabled the company’s third-quarter profit to exceed analysts’ estimates. On average, they projected a profit before some costs of 17 cents a share, but Yahoo reported 21 cents a share. Unfortunately, the rest of the report wasn’t quite so rosy. Sales, for example, dropped more than four percent to $1.07 billion, which at least matched the average estimate. Another bright spot in Yahoo’s financial report came in the form of a continued agreement with Microsoft. This revenue per search agreement, originally scheduled to…