Would it be enough for me to focus mainly on free website SEO, without involving paid search optimization (PPC ads)?

The short answer is yes, I personally believe that running a proper free website SEO strategy can be fully sufficient to keep up with a sharp online competition – even without fueling your overall digital marketing effort via paid search optimization/promotion (otherwise, Pay-Per-Click ads). What’s more, while PPC ads can also be very useful at some point (for example, like A/B performance testing for your core target keywords or, say, in the capacity of a nice kickstarter giving initial search traffic flow for startup projects), free website SEO (otherwise, organic search optimization) is a MUST for any online project, whether it’s simply providing information, acting as a supportive source of content marketing, or directly earning net income. 

Put simply, there is no point in wasting time, effort and money to create and maintain a business website or marketing blog – when nobody can actually click on it directly from Google’s organic search listing, right? That’s why focusing on driving organic search traffic with free website SEO strategies should be your strongest priority, in line with considering paid PPC ads only as the optional source capable of instantly providing you a temporary boost in paid search traffic. So, all that being said, below I’m going to quickly outline all the primary ranking factors of organic SEO considered by the search engines before anything else – for you to get focused when running free website SEO strategies and get better chances of maximizing their positive impact on your long-term rankings. 

Organic Ranking Factors to Be Focused with Free Website SEO

Before anything else, I recommend considering these major factors that determine your ranking performance in Google’s organic SERPs. So, here is what the search engines actually want to see on your website:

• High-Quality Content – every shred of your body content (i.e., web copy itself, as well as the main on-page SEO elements like Title Tags, Meta Descriptions, H1/H2/H3 Headers/Subheaders, Image ALT Tags, and Link Text Anchors) are to be well-written and rich with your target keywords embedded organically (I mean without compromising with good user experience, for example, when it comes to “keyword overstuffing” – that’s simply not working anymore).
• Website Code and Structure – these ranking factors are generally related to domain name/extension, hosting server, page loading speed, mobile responsiveness, user/spider accessibility via clean & concise interlinking structure, sitemap, schema.org markup, etc.
• Social Media Presence – is related to all factors of popularity and user engagement coming from the leading social websites and media platforms, such as the number of shares, likes, authority mentions, credible link sources, etc.

• Backlink Profile – external links created (otherwise, “earned”) organically are considered by Google itself as arguably the third most important category of ranking factors ever. So, the number of relevant backlinks coming from authoritative and credible third parties with strong Domain Authority and high PageRank will be the most powerful assets that are driving your off-page SEO strategy, as well as the overall organic ranking progress in their own way. That’s it.