Promoting LinkedIn pages

For my new adventure with the LinkedIn Pages I have several ways to increase the number of followers.

• I can pay money to LinkedIn to promote the page. I don't plan to do this in the near future. Partially as I see sponsored post for pages with very few followers. I don't see that the number increases for them.
• I can invite my immediate connections at a rate of 100 people / month separately for each LinkedIn page. (Actually more, as I get back the invitation credit every time someone has accepts the invitation.) I am doing this, but some of my contact don't use LinkedIn too often and others don't use the given programming language any more. In any case at that rate it can take several years to invite all of my contacts.
• I can refer to the new page from my own profile. I did it already already and that too brought in a few followers.
• I can publish content with the appropriate hashtags and hope people will see it and decide to follow the page.
• I can hope that the content I publish is "like"-ed or re-shared or that people comment on it and that way even more people will see them.
• I can post in LinkedIn groups relevant to each subject. For example there are several DevOps-related groups. LinkedIn does not allow you to @-link to pages in the groups but I can include an external link leading back to LinkedIn.