I have website with events catalog. Each event has a seperate page. As event passed, page is deleted. Daily update results in disappering of hundred pages and appearing of hundred new pages. In WMT I always see thousands of 'page not found' crawl errors, because crawler tries to fetch pages which already have been deleted. How can I spend my Google crawling budget more effectively? How can I direct crawler to live pages, not to deleted ones? I do link building. The site has daily updated Sitemap. What else can be done?