Could you expand a bit?
Sure!
When you send your first e-mail, your weight and the current date are logged.
You can send it in pounds (it's the default unit) or in kilos (you have to specify 'kg' or 'kilo' then).
You will then receive a confirmation e-mail with a link to your profile.
Then, every day you will receive an e-mail to remind you to log your weight.
And every time you do so, you will receive a link to your updated, private profile.