I briefly used Microsoft's Azure Bing custom search engine, or whatever they call it. I found the support to be extremely responsive and reasonably knowledgeab

I briefly used Microsoft's Azure Bing custom search engine, or whatever they call it. I found the support to be extremely responsive and reasonably knowledgeable, even though I was only spending a few hundred a month. That said, the actual product features and terms of use were both significantly behind both Yahoo BOSS (which uses the same Bing index) and Google's search API. (One particularly terrible term was that you can't use it on pages with any advertising besides Yahoo/Bing ads.)