Can someone explain social signals and their signifigance with SEO

That are basically Social Shares, you buy social shares that means your post will be shared on what so ever basis you have decided. Social sharing cannot be considered as black hat or grey hat from Google point of view. But yes from seo point of view that is wrong. This can affect rankings but not necessary. This cannot be considered as grounds for penalty.

Social signals are the likes & comments that helps to amplify the connection of a website worldwide. It connects the people of different cities or countries to your site without harming your current ranking. Most importantly, the shares are powerful than the likes & comments that helps to reach out the audience whom you're not targeting. Most of the SEO professionals like to get social signals on their site to get indirect traffic from social sites easily.

They are somewhat effective as per the current data researched by the professionals. Must check Google for getting the precise info of it.

Social Shares are good for your websites as they tell search engines that you are been shared and discussed in the internet. This could help you in building links in future, and everything would look organic.

Also I have experienced ranking rise with just social signals also so I just pick them everytime.

Concerning the effect on rankings.
The discussion on whether or not social signals affect rankings directly is ongoing, and some experiments seem to prove it's causation, not correlation. Google's never confirmed it, but for sure pages with more social shares rank better and it is becoming a part of Google's algorithm.
The main benefits of social media lie in the buzz you make and the direct traffic that you get as a result so you will only benefit from this.

From what I know there`s no proven impact on rankings from the social media likes and +1s itself, as well as there`s no direct seo value from nofollow links spread with shares and re-tweets (apart from relevant audience and traffic you can get still, creating content wisely).

On one hand there`s Google denying any impact, on the other hand - lots of studies and experiments proving the correlation of page/article social media engagement and its ranking success. There`s no way to know for sure, but this basically seems logical the other way around: in case your content has many shares and likes, this probably means there are some relevant links to it and there`s actually something worth sharing. Which means that you have put some effort into creating a piece of valuable and unique content. Which, in its turn, might be the initial factor to rank your page.

In case you only get paid signals - this will probably have little to none positive effect. The main idea here, in the first place, is to create the content that encourages users to share and discuss it naturally.

I've heard about people on here having success using social signals from PBNButler. It appears they are better than fiverr's because they get real shares through an app deal they have. Anyone have any success with these?
How many social share should someone buy?
is it an ongoing thing or just one time as part of link building strategy

I truly believe that social signals play a pretty good role in the seo process.
You can not deny that social signals are a part of the greatness of the content.
If an article gets so many shares, that's because it's very helpful. And Google knows that .
social signals has significant effect on SEO. Also, the weightage of signals keep changing in the current SEO world.

Social signals refer to a webpage's collective shares, likes and overall social media visibility as perceived by search engines. These activities contribute to a page's organic search ranking and are seen as another form of citation, similar to backlinks. With this indirect impact on SEO, a lot of people speculated that content that gets a lot of social shares may be seen as more valuable content by the search engines.