The great way of marketing and self-promotion is connected with designing web templates.
Very popular are free templates for Wordpress or Blogger.
They are relatively easy to create and usually in the footer designer places the link to his own webpage,
so besides the advertisement theme designer gets the free link, that counts in SERPs.
The more popular template, more links it brings to the creator.
Some unscrupulous people try to sell the footer link, and now you have three or four links to unknown places,
that is vere easy to be punished for by Google.