Full disclosure: I run a naming company. But that doesn't mean I'm trying to sell you.
Obviously your problem is going to be the word LUST as the first 4 letters of your name. To be completely honest, a daily deal site named "Lustomer" makes me think you sell adult merchandise or something.
If you're targeting anyone other than SF hipsters, you're going to have a problem. It's really scary how out of touch (or inexperienced) the people saying it's a good name are. This is basically the equivalent of naming your company ShitHeadwear. A cute pun? Sure. The name for a serious business that's actually going to sell things to real people? Not in a million years.
Can you imagine going up to Joe Schmo, a local business owner who's 55 years old, slightly conservative, and wears a suit to work everyday, and asking him if he'd like to use your product called "Lustomer"? Even if he's willing to look past the name, the fact that you chose it reflects very poorly upon you. This is his business we're talking about - he works 10 hours a day and spends most of his time at the office. And he's going to trust a company with some ridiculous unprofessional name? Yeah, not gonna happen.
This is reminiscent of Fukime, except your name is probably worse. Definitely change it before you get any further.