I'd like to suggest that you add a second
supplementary question to this follow-up survey. Give
respondents an opportunity to indicate how swiftly they
received a reply from their MP, eg same day, within two working
days, within a week, or other period. You could then use that
data to highlight how some elected representatives are better
than others at timely engagement with those they purport to
represent.
In my own case I used the site recently to write to Desmond
Swayne (New Forest West). I was seriously impressed to
subsequently receive a personal email reply from Desmond within
30 minutes (that's right, 30 minutes!) of your despatching my
communication to him.
There's a great example of how your measurement might be
enhanced, showing the Desmond Swayne is e-communication savvy
and ready, yet currently there's no means of distinguishing
between MPs and their responsiveness. Until recently Julian
Lewis (New Forest East) was my MP. You were fortunate if you
received a written reply from Mr Lewis within seven days of
writing to him on constituency matters!