I'm wondering if its time to optimize my websites for bing. Looks like google search results have been getting worse and worse. http://www.webpronews.com/google-appears-to-be-busted-with-its-own-paid-links-again-2013-02
Way more people use Google so ranking well for a keyword in Google will bring you a lot more traffic, for this particular reason there is more competition so if you want a search engine which has a higher "traffic cap" try to stay with Google. If you want to rank easier but get less traffic, go for Bing.
I think they are allowed to engage in paid links. Because as stated by Matt Cuts, paid links that passes the pagerank are influencing the algorithm and can manipulate it. In this case Google is the search engine and it cannot be manipulated itself. And what about Google Adwords, aren't those already paid links. It's called advertising.
The thing is it is really very hard for Google to manage billions of pages which are indexed in it, however, we should appreciate their work..