You know, in thinking about this, who cares about number of visitors? It's about as helpful as number of return visits or bible studies. What matters is number of actual converts. Professional companies who look at their website statistics only view the number of unique visitors as a portion of the equation. It's called a conversion rate. What's the conversion rate? How many of the visitors become actual, paying customers?
The Bible doesn't have any passages that describes the number of people the disciples talked to, or the number of return visits, or the number of Scripture studies (they didn't have a Bible back then). They only reported the number actually baptized.
My point is, stating the number of visitors is simply a way to boast, and really means nothing. Of COURSE there's going to be an increase in the number of visitors with this campaign. No question about it. Draw attention to any site and more people will visit it. Briefly. In a month or so, the number of visitors with drop back down to the normal range, possibly a little higher. The more important figure is the number of people where are actually converted due to their exposure to the website as the FIRST introduction to the religion.