Tumblr.com was clever because the right vowel was dropped in the right place at the right time, hence the success.
dpwnloads.com is just insulting. Am I supposed to think that the top of the 'p' looks like an 'o' and the stem of the p is supposed to indicate or convey the message of 'down'? Well now that I look at the 'p' in that perspectictive I will give the name a pass. The only way this clever concept can work is in the Logo. The stem of the 'p' is really going to have to look like an arrow of some kind to indicate 'down'. Very Funky Lazers, the name is worth nothing but the idea is awesome, this was your intent with the 'p', yes?.
Regards.matt