  Searching for medical information is both a common and important activity
since it influences decisions people make about their healthcare. Using search
engine optimization (SEO), content producers seek to increase the visibility of
their content. SEO is more likely to be practiced by commercially motivated
content producers such as pharmaceutical companies than by non-commercial
providers such as governmental bodies. In this study, we ask whether content
quality correlates with the presence or absence of SEO measures on a web page.
We conducted a user study in which N = 61 participants comprising laypeople as
well as experts in health information assessment evaluated health-related web
pages classified as either optimized or non-optimized. The subjects rated the
expertise of non-optimized web pages as higher than the expertise of optimized
pages, justifying their appraisal by the more competent and reputable
appearance of non-optimized pages. In addition, comments about the website
operators of the non-optimized pages were exclusively positive, while optimized
pages tended to receive positive as well as negative assessments. We found no
differences between the ratings of laypeople and experts. Since non-optimized,
but high-quality content may be outranked by optimized content of lower
quality, trusted sources should be prioritized in rankings.
