There are many webtools sites like checkpagerank.net or marketleap or pingoat that offers free tools to check your pagerank, link popularity, traffic , ping your site, value of your website etc. IMHO, I don't think these sites (especially those with only 1 tool like checkpagerank.net) make big money... maybe at most $xx per mth So maybe sites with multi-tools like iwebtools can make more ..maybe $x,xxx or $xx,xxx per mth) Any who runs a profitable web tools site care to share?