IPVenger protects your WordPress installation by blocking access by IPs associated with high-risk behavior.
The majority of these requests originate from Botnets which blindly crawl the Internet looking for vulnerabilities to exploit, and can repeatedly attack the same site from different IP addresses. In cases where a site has relatively light traffic, the number of attacks can easily exceed the number of legitimate visitors.
If you received an Appeal Request email, it means that a visitor to your website was initially blocked and they are requesting access to your website.
The vast majority of web traffic that is blocked by IPVenger will be automated bots and malicious traffic that won't bother to try to get past this form. However, sometimes legitimate visitors may be blocked. This could happen because they are behind a proxy or because they have an unknown virus.
When this happens, you have the ability to grant the visitor the ability to reach your website. That's where the appeals process comes in.
When a website visitor is blocked due to a high IP score, they will be presented with a page that displays a message and a form to submit to request access to your website. Through the IP Control Center, you can grant the visitor permission by selecting the "allow" option in White/Blacklist column dropdown for their IP address.
When a visitor comes to your site for the first time, the IPQ score and other data about their IP is retrieved from the IPViking server which takes microseconds. The wait time is subject to typical network latency. Once the user has established a session, the overhead is negligible.
IPVenger and Google Analytics count traffic in fundamentally different ways. Google Analytics attempts to count unique, human visitors to your site. IPVenger counts visits from automated agents, users with scripting disabled, and legitimate human users. Together, IPVenger and Google Analytics provide you with a complete picture of your site traffic.
Only IPs with a history of risky behavior are blocked so "good" bots and crawlers will have access to your page and will see exactly the same content they would without IPVenger protection. Traffic from some high-risk content aggregators may be blocked, but current search engines reduce the page rank when they detect inbound links from these "black hat" sites, so the net effect is likely to be positive.
Just go to ipvenger.com and sign up for an account.