What are your reasons for doing so?
I'm not really a big shopper, but I love the convenience of shopping without leaving my chair. I *hate* crowds and that is pretty much most shopping centres. Living somewhat in a shopping backwater, I can also get a much bigger range and usually at a better price than I can get it locally.
What sites do you prefer and why?
I do like sites that have obviously built a business around their online site, rather than being an additive to a bricks and mortar business. Sites like amazon.com have such a wide range and also having the recommendations section makes it (slightly) easier to buy books from Authors you've never heard of...
If I'm buying computer bits I'm much more likely to be driven by price so if there is an option to list items by category and sort by price that is good (e.g.
www.estore.com.au).
I have a list of DVD/CDs sites and I have bought from most of these - just about purely based on price:
dvdboxoffice.com
cd-wow.biz
ezydvd.com.au
devoteddvd.com.au
Given that I *know* what I want to buy in this case, the only important thing is a good search facility.
Is there anything that convinced you to buy something when you normally wouldn't? (Evil question, I know.)
Nope - I'm pretty thrifty and I'm unlikely to impulse shop at the best of times.
How do you research what you are going to buy?
Even online, I have a pretty good idea what I'm looking for, though I have been known to browse for books on amazon without any specific item in mind (usually gifts - my brothers both have similar reading tastes to me, and anything I buy for them will end up back to me eventually).
What kind of products do you buy? Electronics? Media? Clothes?
DVDs, music, books, computer bits inc. software/games, sporting goods.
What's the most "personal" (something that you're picky about and usually need to check out in person before you buy) item that you've purchased online?
I bought a shirt once. It fits and looks pretty good. Am I picky enough to care. This was from cafepress.com.
edit: I have also bought groceries online, but only when the kids were small. I found both major supermarket chains delivery sites relatively hard to navigate/find things on. The search function sucked, but it was still better than lugging tiny babies out to the shops...