I am yet another victim of the MGS-Groupon sham. After paying the upcharges for the work, Mark showed up, did half the work before calling it a day because of high winds. No problem - he promised to come back the next business day. Never showed. All my entreaties via email, phone, text, Facebook, Twitter and now HomeStars - no response whatsoever. I had to touch up the work that was done already (way too many smudges and runoff left on the windows) plus clean and reinstall all of the screens that he unhelpfully left out so he could clean them in his return visit. Thanks for nothing! Avoid them like the plague. This is an illegitimate, fly-by-night operation that should be banned from offering discounts since they clearly cannot deliver on the volume. My suspicion is this is a one-man operation and that there is zero infrastructure/workforce behind it. Not a good combination for ensuring delivery of a service already paid for in advance.