The two main units of traffic measurement are views and unique visitors. A view is counted when a visitor loads or reloads a page. A visitor is counted when we see a user or browser for the first time in a given period (day, week, month).
You may notice that weekly unique visitors is less than the sum of daily visitors for the same week. This occurs when the same visitor appears multiple times during the week.
You may also notice that your visitor count lags behind your views count. This is due to the way we are currently crunching the numbers. Typically a view is reported within five minutes, while it can take up to two hours to report new visitors.
Do you have specific dates when you ran these tests? Also what was the specific link your friends used to access your site - was it http://jtweaverblog.wordpress.com/ ?
Let me know if you have any questions.