Dive Brief: 

• Brands and advertisers still aren't sold on social blogging site Tumblr's ad products. 
• Since Yahoo purchased the site last year, Tumblr has rolled out native ads, ad targeting capabilities, and pay-per-engagement options. 
• Despite those improvements, advertisers cite limited targeting, a lack of Tumblr-ready content, and the site's failure to appeal to brands as reasons they don't utilize the site.

Dive Insight: 

Tumblr could certainly work on some of the bigger problems associated with advertisers' lack of interest in the site. Creating better analytics is a perfect place to start. As far as content goes, brands and advertisers may be on their own, but there could be a huge opportunity for either Tumblr or a third party to offer content customized for Tumblr. Overall, the social site is sitting at the base of a huge mountain of opportunity.