It really depends on your business niche, budget, and the goals you have for it.
Paid advertising can be more effective if you know how to use it, likely expensive too; but SEO takes a lot of time and effort to rank high on Google. SEO is the way to go if you want to rank high on Google and also establish as an authority or industry leader.
If you are looking for quick results and results that will bring you instant traffic, paid advertising is the way to go.
If you are trying to attract high-quality leads (i.e. leads who are more likely to sign up for your newsletter, purchase your products/services), SEO is likely to be more effective and also cost-effective than paid advertising.
Ultimately, what is best really depends on your business and marketing goals.
Pro-Tip: If you're starting a new business, it may be better to focus on SEO first, then launch your paid advertising campaign. This will give you a head start in the search results and create brand awareness among potential customers.
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