Another week, another search executive leaves Yahoo (NSDQ: YHOO) and joins Microsoft (NSDQ: MSFT). Dayne Sampson, Yahoo’s vice president of operations for search and advertising, will join Microsoft’s Global Foundation Services Group, which deals with the backend of Microsoft’s online properties, including search, according to AllThingD. Sampson is the fifth Yahoo executive that Microsoft has confirmed it has hired in the last several months; last week Jan Pederson joined as chief scientist of Live Search. But that’s not the full extent of it: During the company’s strategic update in late February, CEO Steve Ballmer said that Microsoft had hired about 10 “key technologists” from Yahoo. If the two companies ever get around to combining their search groups, at least the transition should be a lot easier.