The current value of link counts as supplementary measures of the formal quality and impact of journals is analyzed, considering an open access megapublisher (MDPI) as a case study. We analyzed 352 journals through 21 citation-based and link-based journal-level indicators, using Scopus (523,935 publications) and Majestic (567,900 links) as data sources. Given the statistically significant strong positive Spearman correlations achieved, it is concluded that link-based indicators mainly reflect the quality (indexed in Scopus), size (publication output), and impact (citations received) of MDPI’s journals. In addition, link data are significantly greater for those MDPI journals covering many subjects (generalist journals). However, nonstatistically significant differences are found between subject categories, which can be partially attributed to the “series title profile” effect of MDPI. Further research is necessary to test whether link-based indicators can be used as informative measures of journals’ current research impact beyond the specific characteristics of MDPI.