We are looking to place a value on our startup as we seek a round of funding. The startup was seeded on sweat and roughly 50k, and we expect to take 300k-500k to expand our coverage and services and work on the venture full-time. Coincidentally, PG defines this as the median range of investment for startups coming out of YC in his "Why There Aren't More Googles" essay.
I will try to be informative but discrete. We had between 1 million and 5 million unique visitors to our domain between Aug 15 and Sept 15. Our map is used as an embeddable widget on 400+ other sites, many of which are well-trafficked media outlets, and our map has been used on CNN during their hurricane coverage. O'Reilly also happened to mention our site during his Web2.0 keynote. Also, we have received hundreds of voluntary tips, donations, and thank-you emails.
So what percentage should we expect to hand over for this size investment?
* If your team has a successful start-up track record, and if you have a 2-5 person management team with significant e-business or technology experience, your pre-money valuation jumps into the high single or low double-digit millions. $6 million to $15 million is the typical valuation range, and you should be looking for a first round of $3 to $10 million.
From: http://oz.stern.nyu.edu/startups/vc.html