Today I have just done a search with "internet marketing forum" keyword on google

But pretty strange for this site "Webmaster Sun", they are on top #1 for this keyword, see the picture

and have a look on their site, they only have Threads 8,500 threads while other forums have millions of threads/posts

I want to know what SEO techniques they have applied to get first position on Google so I can apply for my blogs.

Any advice?

Thanks in advance.