Traffic discrepancy

[BREWSTERS]

I put a basic holding page up for a domain a few months ago. The daily stats show average number of daily visitors as;

Dec - 16
Jan - 18
Feb - 23

I switched the nameservers for a few days to a parking page and traffic was barely 1 visitor per day. Switched back to the holding page and it's straight back to previous figures.

Is the parking co discounting traffic (spiders, bots etc) and would a crappy holding page be getting 20 spider visits a day anyway?

Any insight welcomed, thanks.