I have a 35 day old blog on Tumblr. I submitted it to Google using “Add your URL to Google” page about a month ago, but Google can’t crawl my blog.
There are lots of SEO tips which you caan find in google. But what counts the most is a great content about the topic it has been written. While tagging the posts think of keywords you would search to reach that particular article. Follow blogs of your interest and some of them may follow you back ,thus, increasing traffic. Making a facebook page and twitter profile would boost up your traffic.
It is not a fast process:
When you submit the URL , you one of the billions submitted.
quality contents is better than SEO tricks.
Gooole shows popular and quality content, so
You can use social networking sites to promote your blog, if you have quality content, you will become popular, and then google will feature you.
it is easier than first getting featured by google and then becoming popular.
one of the tricks: ask a question with yahoo answer, and then answer it with your link.
Related links about crawling etc.... what google said about this :
Dedicating much time and money into the organic SEO of your Tumblr blog is not the best investment, in my opinion. The nature of reblogging nature of Tumblr makes for a huge ecosystem of exposure. Rather than trying to naturally rank in search engines for your blog, I'd suggest focusing more on your content and base of followers. Gradually, it becomes exponential. Queue your posts accordingly and work to get attention of bigger blogs in your same niche. Sometimes, I single reblog from a huge Tumblr user can trickle followers your ways for months to come, and from there on maybe even forever.
Also, if your blog has been active on Tumblr for over a month, chances are it is indexed in Google. Check out this article on using operands to better target your site in Google's results to see if it is indeed indexed: http://www.makeuseof.com/tag/master-the-google-search-like-a-god-save-time/
If you're convinced that you need to optimize your blog for search engines still, one big step that I would recommend is to place your blog on your own custom, keyword-conscious domain name.
Since a tumblr account uses a subdomain of tumblr, you don't want to purchase any optimizations specific to the entire domain. Rather, read How To Become Tumblr Famous. It looks pretty straight forward.