Digital marketing is the marketing of products or services using digital technologies on the Internet, through mobile phone Apps, display advertising, and any other digital mediums. Digital marketing channels are systems based on the Internet that can create, accelerate, and transmit product value from producer to a consumer terminal, through digital networks.
That's why PA and DA metrics often vary from tool to tool. Each ad hoc keyword tool we tested came up with slightly different numbers based on what they're pulling from Google and other sources, and how they're doing the calculating. The shortcoming of PA and DA is that, even though they give you a sense of how authoritative a page might be in the eyes of Google, they don't tell you how easy or difficult it will be to position it for a particular keyword. This difficulty is why a third, newer metric is beginning to emerge among the self-service SEO players: difficulty scores.
Over the past few days or so, I have been seeing chatter both at WebmasterWorld and Black Hat World around ranking and traffic changes related to Google organic search. I got to say, I doubt Google pushed anything specific this week or even next week. Rankings do change by itself and new content is always being added to the index but an algorithm update - I doubt it.