Yes, I'm doing this one.
If memory serves, it was about the time of the airing of this episode that I became involved with Equestria Daily and the fandom at large. Though we were still mostly confined to 4chan's /co/ board, the community was showing signs of spreading to other corners of the internet. I hesitate to call it an invasion, but that's essentially what happened. Not to repeat what the other posts have said, but February and March of 2011 was when things really started to pick up.
This episode in particular was an exceptionally important one in terms of character development for Rarity, for up until now she had been known and identified simply as the fashion horse with the undrawable mane who whined a lot. Entertaining, but shallow- I'd dare say the majority of the opinion of her prior to the airing of this episode tended towards the negative. Thankfully, some actual writing and storytelling that went a little deeper than the deep end of the kid's pool, as well as some superb acting by Tabitha St. Germain, solved that almost right away. She may not have jumped to the top of everyone's favorites list, but it seeded the roots of respect for her character.
We were also given the fantastically-composed and oft-remixed song Art of the Dress, which also (unfortunately, to many) gave birth to one of the most often-repeated lines from the show. No, I'm not linking it, you know what it is.
After the break you can catch the episode in its entirety.
