Excluding URL from sitemap

Selected answers from the Dumb SEO Questions Facebook & G+ community.

• 
  vouchers code: Hello,
   ;  ;  ;  ;I am running a coupon code website, where I add 10k+ vouchers daily and every voucher has a separate url
  for eg www.mysite.com/coupon-get-20-percent-off
  
   ;  ; I don't add this url on sitemap and prevent to crawl as these offers are active for few day. ( 1- 30 days generally ).
  
   ;  ;Now If I want to add these urls on google webmaster to crawl, will it affect my site?
   ; What should I do when that url get removed or my offer get expired?
   ; What should I do? Please advice me.
• 
  Edwin Jonk: If you add pages to search engines it will affect your site.
  
  My concern would be the quality of those 10k+ voucher pages. Can you consider them as little or no original content?
• 
  Suraj Gadage: +vouchers code ;Generally Google can crawl your website Without sitemaps - a search engine visits your site's pages through links on and off the site. ;
  
  If you start adding URLs in the sitemap or in webmaster tool (thorough fetch as Googlebot), there won't be any problem. However, search engines may or may not index particular pages because of lack of the necessary components for inclusion like page content, link strength, etc.
  
  Now coming back to your question where you want a solution for the pages that will be removed from the server (after offer expiry):
  
  Check if your website CMS has the ability to add custom rules like, adding an expiry date for each coupon code page that goes live. After the offer expiry, the pages get removed from the server and all traffic is lead to the specific section with a 301 redirect. ;
  
  Why this recommendation?
  
  I work with a similar client who has the same the type of website. Interesting thing I noticed about coupon codes website is that they get backlinks very easily (I'm talking page level backlinks and not domain level). So I would not want to lose the link value.
• 
  Edwin Jonk: +Suraj Gadage ;do you use ;unavailable_after meta attribute as a way to noindex after some period?
• 
  Suraj Gadage: +Edwin Jonk ;Yes.