Not to hard, I think you should have about 500 uniqies per day (toolbar should be installed for your visitor browser as well)
How about Alexa 1000 ? Is it hard to achieve ? How many unique visitors should I have daily to achieve that ?
When you say 100,000 to 300,000, are you saying this number of users who have Alexa toolbar, or just any users ? If any users, how can Alexa measure ? If tolbar users, will there have so much toolbar users ? Why one need to install Alexa toolbar as it has only a popup blocker which is now build in in IE and FF !!