Business first. The name of this place is Tile Outlet and it should not be confused with Tile Outlet, Always in Stock, which is some national franchise outfit.
Similarly, the website address listed here on Citysearch is also wrong. Tile Outlet on Fullerton Avenue in Chicago, Illinois, has a web address of www.tileoutletchicago (put dotcomm at the end - Citysearch won't let me type the web address) I know these two things because I had a devil of a time finding them on the web yesterday, thanks to the misinformation listed here. At least, the phone number is right.
So, I was there Nov 7. The variety and assortment seems to have dwindled. The choices are much more mainstream and common than the place has had in the past. The good news is, if you're looking for glass tile, they've tripled their inventory of styles and colors. The bad news, there's a lot less interesting marble mosaic and what they have is what you can get anywhere.
Shop price, people! Some of the very common marble types are available at Home Depot and Lowes for less, just because they have huge buying power. In general, Tile Outlet is a bit cheaper on most stone and ceramic, but I'm not current on the prices everywhere for glass tile, because I don't use it in old-house restoration projects.
Getting assistance can be spotty. The trade-off is price. If you know what you want, shop here. If you expect more than cursory design advice or you require stellar service, go to a tile RETAILER. Also, if you see something you love, buy it now, or at the very least, first thing tomorrow. Once something sells out, there is NO guarantee they will ever have it again in that color, or size, or shape, or whatever. Do NOT wait a few weeks to go back and buy that pattern you loved. It may be gone forever.
And, walk your chosen tile to the window, to see what it looks like in natural light. The glare from the overhead florescent lights is cold and distorts color.
In general, I like the place. I've been going there since my dad started dragging me along on his projects, at least twenty-five years now. It's not pretty, but it has a decent selection and good prices and a few nice people who will help you load your car/truck.