website = from advertisment to content...really?

I attended a webinar yesterday – Optimize Your Site for Maximum Lead Flow created and presented by Tim Ash and Mike Volpe from Hubspot
Tim and Mike shared a lot of interesting information regarding SEO. Things everyone who is writing a blog/maintaining website/etc. should know.
Some info. worth to remember:

make sure you know your buyer persona

focus on your content

did you know that more people will visit company’s website if the company provide blog too

cut down text – people love content but you cannot overwhelmed them with it

CALL TO ACTION – don’t forget to add that on your page

I need to agree to what those two said during the webinar. I also noticed that almost everywhere people are talking about content and less about advertisement. There are social media voices which are explaining to us that investing money ONLY in ads won’t give us too much except loosing money….but investing in good content will bring more and more people to your website.
My question is how much we are drifting towards content and from advertisement?
Why there are still so much money invested in advertisement?
If we know that content is a MUST why we still putting money in advertisement?

website = from advertisment to content…really?

klaudia