How to detect if site was spammy - SEO expert

Hi

Can anyone please tell me How to detect if site was spammy or on the brink of being spammy? Is there really a thing since I just encountered it now?

Another Question is

How come the SERP was there but the number of the visitor is just too low?

Any Advice?

Thanks a lot

You can tell by whether they are keyword stuffing, hiding code etc.

If you show up on the SERP, you may have low visitor counts due to that they keyword simply has little traffic, and also you may have a title showing that is not interesting to users… In addition, to really get the traffic from a keyword you should really be in the top 3 results.