Blogging service Tumblr has raised $4.5 million in a second round of funding from its current investors, according to a report on AllThingsD.
Union Square Ventures and Spark Capital ponied up another round, bringing the company's total VC funding to $5.25 million and giving the company an estimated valuation of $15 million, according to the report. Tumblr provides a means for people to create, edit, and post blogs.
Tumblr is a free site that reportedly is leaning toward developing premium services to sell to its members, rather than latching onto an advertising-based revenue model.
Founder David Karp is aiming to generate revenue early next year, according to the report.
That should bode well for the company, which earlier this year launched a new feature that provides bloggers with the means to let others add content to their blogs.