Thousands of empty customer records created every day

@nguyendinhchinh
This looks like a good solution.  Hopefully the team will review and adopt it.
A few comments ;)
1) can IWebHelper be injected (rather than Resolve() )?

2) a little cleaner

var guest = _customerRepository.Table.FirstOrDefault(x =>
    x.LastIpAddress == currentIpAddress
    && !string.IsNullOrEmpty(x.Username)
    && !string.IsNullOrEmpty(x.Email)
    && !x.IsSystemAccount);

( .Where() will never return null, so no need for "?")

3) RE:  " can Disable the DeleteGuests task as it will no longer be needed."
There are a lot of IP addresses out there (that may never come back).  Best to adjust the customerSettings.DeleteGuestTaskOlderThanMinutes to be very large ;)

nguyendinhchinh wrote:

Thanks for the suggestion. Here is a work item to discuss.