How much of a difference will a dedicated IP make for my website's SEO? There are a few hundred websites on the IP address provided by my ISP currently.. wide range of types. Would I see a 20% performance improvement on average? another percentage? Thanks.
It is impossible to give a exact percentage. There are too many factors. So it will vary from case to case. I think a lot of it would depend on the quality and topic of the other websites sharing the ip. If the other websites are spammy or questionable topics, it could have a drastic impact. If the other websites are high quality, it would probably have very little effect.
Personally I like having a dedicated server because of the reliability, and speed. Which I do think makes a big difference. As far as having a dedicated IP, I don't think it matters.