What are obsolete methods of Link Building in 2018?

Is it really a good idea to start our ad campaign with in-line text ads? We will be doing ad campaign for the first time.

Investing in Unique Content, is it wise? I mean its okay if you get unique content. But those are very rare cases that happens. And not to mention what I see is that all the content around the internet is well rewritten or republished.

New Customers vs Existing Customers, which ones are easy to get sales from?

How to increase Customer retention?

Do you think that for branding purposes mobile marketing and mobile optimized sites are utmostly necessary?

Hello friends-How to visible website in google search results? This is website domain <!-- m --><a class="postlink" href="http://www.skypesupporthelp.com">http://www.skypesupporthelp.com</a><!-- m -->. It is visible ramaining search engine results like- bing, yahho, yendex but still not visible in google. It has up to 3000 backlink, when we do search engine submission then its visible in google but after 1 to 2 days It is to be invisible in google, so please suggest me some authentic solution to fix it. thanks

How to visible website in google search ? when we do search engine submission then its visible in google but after some day It is to be invisible in google, so please suggest me some solution to fix it

Email marketing

I see a plenty of sites which doesn't have a mobile version or not mobile optimized.