I think by now, most of the principles of SEO are more or less well understood by people that have done their time in the trenches since 1999, although new platforms and data types arrive all the time keeping the need for ongoing practice or testing even more important than in the past. The need to learn about new entrants like Siri, Alexa, Facebook, Linkedin, and specialist search engines (like Booking.com, for example) will keep SEOs on their toes for years to come.
"I hope the new site and optimizing keeps it rolling! You guys have done an awesome job! If you have any more suggestions count me in. I don't know if you remember but my goal was to get 2000 natural applications a month by year end. August we had 1200! March we had under 50! Unbelievable! Next years goal is by year end is to be getting 4000 a month. Then I take you, a member of the link team on a weekend trip for some fun all expenses on me." Melissa E. https://businessinsightsdigitalmarketing.tumblr.com/