Post
Posting is the most important activity on Tumblr. No posts ? no traffic ? no money.
You should only post photos that are related to your niche.
In the description of the post you can then post a link, e.g. an affiliate link. Do not post the same URL over and over. Instead, you can use an URL shortener or buy an additional domain.
Tags are also very important, as they will determine with which search terms Tumblr users can find your post. Think about which tags could fit to your niche and to the image you are posting. Then type in the tags into the search and check how much likes the other pictures there have. If it seems too few, better search for another tag.
I always use 5-7 tags per post although some people claim that tags after the 5th tag are not considered anymore.
Like I wrote under ?Reblog?, the daily limit for posts and reblogs in total is 250. However, there is also a limit regarding daily photo posts (150).