Find at least two (2) peer reviewed articles, or four (4) reputable websites (not blogs), on search engine uses in digital marketing, both SEO and SEM (online paid advertising), and how they have had an affect on SMEs (small to medium enterprises). Your post's conclusion should state whether SEO or SEM has been more beneficial according to your research, or if you find that it is still unproven that one of the two techniques is better than the other if that is your conclusion (include explanation).