1) Email accounts – In practice, an email account hosted on your website gets more than 25% emails than an Hotmail one and more than 15% or more than a Gmail account. There are multiple causes for that, especially that public email providers have spam rules and lists in the place that reject email that may look like spam or come from questionable sites. So you may loose as much as 25% from your success rate just for not using your own email address 2) Proxy provider – If you are using public proxies or even shared ones I’m sure you experienced a lot of failed connections or hang registration just because this proxy die or get saturated pretty fast. The solution is to post on failed sites several times. I got around 10% more success just by posting to failed sites once again after I finished the campaign. Check the picture below I’ve taken testing my shared proxies. As you can see several proxies are marked as bad but if I test them again are marked as ok. That’s because sometimes the connections are heavily used so proxy server refuses the new connection. If this happens when you post then the website will be marked as failed well, in fact, GSA SER did not even reach the website.