If there is valuable software, database or other asset that is not currently contributing to the income - or will influence the earnings trend upwards - this could increase the price the site reaches at auction. Similarly, if there is an asset that will cease to exist after sale or a license that will revert or end post-sale this could adversely affect the price. If you haven't provided any of those figures then there may not be relevant notes to put this valuation in better context.
If the tone/"personality" of your blog is unique to you it's difficult to sell and that affects the price downwards.
Web businesses currently available for sale at various forums