Tom J. Loverro, a well-known American VC commentator, documented his meeting with Brad Keywell, the founder of Groupon - the grandfather of group-buying websites - in Chicago on his blog. He recorded that Brad mentioned during his speech that the first version of Groupon was just an ordinary blog. "Groupon 1.0 started on a WordPress blog," Brad advised entrepreneurs: "Keep trying, get up after falling down... It takes at least five months to build a program that might work." Tom commented on his blog that Groupon's success does not lie in the website interface and functions that were later crazily imitated, but in its unique "core concept." This is the key factor that differentiates many start-up companies. Lacking a core concept, having only a powerful program can instead confuse one with too many functions.