A customer of ours asked the other day if an SEM (PPC) campaign would help their SEO. Our primary focus is on SEO for Santa Fe and New Mexico clients (we have a handful of clients in Arizona and Texas, too) but we run SEM campaigns for several clients, as well.
The short answer is yes, SEM can help your SEO. But the explanation is a little more complicated than 
that. But…and this is a big but…PPC ads in and of themselves don’t increase your organic search traffic. Confused yet?
When Google sees an ad that is directing traffic to your site, it reads it as paid traffic rather than organic traffic. Hence, paid traffic doesn’t necessarily increase SEO.
But according to the experts at Moz, a few things happen when people see PPC ads in the SERP (Search Engine Results Page.)
• People who see an PPC ad on their search feed may be more likely to click an organic listing.
• People who have previously seen an ad may be more likely to click on it and engage down the road.
• Paid ads can increase the number of links and mentions to a site
But all of these are indirect, or passive.
Which strategy is best? In our opinion, SEO should always be the bedrock of your digital strategy. Most traffic (almost 80%) on Google is organic, after all. It is a slow process, but once your SEO gains traction, the results can be consistent.
SEM is a great strategy when done properly, especially when you have specific calls to action or special offers. It can also deliver traffic in a shorter timeframe than SEO does, which is what many businesses want.
The key takeaway is this: SEO and SEM work best when they work together.