No experience with them as a client, but they are a major player in the market and growing fast. Do they use spam techniques? No idea, but reputation management in general isn't rocket science and as long as the shit isn't seriously hitting the fan already, just creating the properties on social networks, community sites, company profile sites, business directories plus press releases, paid articles etc. and linking all the stuff from your website already creates a little "Digital Fortress" how they call it. I bet less than 1% or their customers have a real reputation problem, so easy money, no need to spam.