If there's anything I've learnt about SEO the past month is that a lot of it is personal opinion. Guy #1 may say that Web 2.0's are the most effective method of ranking your website While guy #1 will say that Social Signals are the key! Does anyone have any input on this, with actual backed up evidence? How effective are social signals? Is there any point in driving them to your website, other than the obvious fact that they give social proof to visitors? Do they benefit your Google Ranking?