Business Web in examples

In the last series , a classification of B2C and C2B communications was proposed. Continuing the topic, I want to illustrate this system with English examples:
B2C | Business addresses consumers:

• Search and contextual advertising: Google Adwords , Microsoft adCenter , Yahoo! Search Marketing .
  
• Behavioral Targeting: Tacoda , DoubleClick , 24/7 Real Media .
  
• Email / rss marketing: iContact .
  
• Affiliate programs: Amazon Associates , Amazon Merchants .
  
• Advertising in social networks: Facebook for Business , MySpace Hyper Targeting , Bebo Open Media Platform .
  
• Starbucks card loyalty programs, Mini social networks on the Ning platform .
  
• CRM platforms: Salesforce , SugarCRM .
  

C2B | Consumers are looking for and choosing businesses / products

• Search on goods: Jellyfish , Shopzilla , Shopping.com , Yahoo! Shopping , SpecialOffers.com , Judy's book (discounts) .
  
• Local Search: YellowPages.Com , Google Maps , Yahoo! Local , Local Live .
  
• System ads: Craigslist , Kijiji , MySpace Classifieds , Oodle , vFlyer .
  
• Recommended systems: Last.fm , iLike , Netflix , Stumble Upon , Amazon recommendations .
  
• Reviews and Reviews: Yelp , CNet , Mojopages , Squidoo .
  
• Wishlists: Amazon , Kaboodle , Eventful (Event demands) , Mozilla Wishlist .
  
• Travel: Wikitravel , Tripadvisor , Kayak , Expedia , Orbitz .
  
• Jobs: Monster , Yahoo! Hotjobs , Etsy (selling handmade'a) .
  
• Finance: Zopa .
  
• Real Estate: Yahoo! Real Estate , Zillow .
  
• Books: Lulu , Librarything , Reader2 .
  
• Poster: Upcoming , Eventful .
  

Questions

1. What projects and directions are undeservedly forgotten?
   
2. How realistic, in your opinion, is to provide a single interface for accessing all C2B consumer tools?
   
3. How realistic is it to provide a single interface to access all B2C business tools?