Got a good tutorial which is in demand. How to market it? Should I sale it or give it away to gain trust for sales of any bigger product?

Unable to scale out negative keywords from Google Adwords campaign!! How to remove it? I am not seeing many options here.

I have been asked by a site owner in our niche to publish a guest post in his sites. He will accept one do-follow in the article. So, here is the question where should put the link? Should I put it in the author's bio section? Or, should I find a relevant place in the content and stuff it in with a relevant anchor text. As, I have been doing a lot of reading in this forum. And people are often suggested here that I should make the links more and more relevant.

I am seeing terrible results for some long tail kw's in our niche which were ranking pretty high but fell to the third or fourth page of the SERP's since this update started coming out. Are you guys seeing this too?

Why link tier 1 links only to the homepage and not inner pages? I have been hearing this concept since a while now. But I didn't understand it. Say, if I want to rank a page then most certainly a link to it will help it get ranked better, isn't it?

What actions do you perform to a newly purchased? You know before starting to market it.

Are there any App listing sites? Apart from play store and all that I should know about

Recently I bought a domain which is in .de, the domain has many articles published in it which gets some good amount of traffic. Lets say that if I use adsense then it shall make $50 per week. Now most of the articles are useless and garbage content. For the niche's sake those useless articles are needed. It will be like writing a book on SEO but not talking about link building or on-page optimization. I hope you guys get my point here. So, what should I do? Those articles numbers are in tons and they create a huge database drag.

How much actual time does it take for a backlink to have effect in the SERP's? Backlink checker tools can take weeks to catch the link. Is there any way to check the link right away after creation?

One of my site just disappeared from the SERP's. The site is almost 3 years old. It has plenty of good content and good amount of regular visitors.

Along with it the site also receives a good amount of traffic from Google which will be around 60% of its total traffic.

I am confused here why our site will disappear overnight!!