I have nothing against group buying sites. Actually, I love the concept! Who wouldn't be happy with discounts and promo packages? But all of us should take extra caution in purchasing deals.
Take for example MetroDeal's most recent offer -- Discover Sumilon Island: 3-days/2-nights for 2 persons, Airfare, Kayaking, Island Trekking, etc. for P9,900 ($200) instead of P19,800 ($500). I took a screenshot of the deal when they just posted it. Only 4 vouchers have been purchased when I snapped this.