Yes, that doesn't seem incomprehensible that a listing could be viewed 56 times in 7 days. Are you thinking this is higher than normal or lower than normal??
The listings can randomly appear in different advertising areas of the site, so it's not out of the realm of possibility, that, with the thousands of users of Trulia, there could be 56 people who viewed that property in a week. And, consider this, there may be 1 viewer who has looked at it several times.
Hope that helps~