Special Unicode Characters in Data Validation Lists: ☐, ☑, ✓, ✔ - This may be my favorite approach. You can include special characters like this in a Data Validation drop-down list. This isn't quite as good as clicking once to fill in a checkbox, but it is great for the mobile Excel apps. The only hard part is remembering how to insert a check mark symbol in Excel. For more information, see my article Using Unicode Character Symbols in Excel.
Be aware that your URL affects your search engine ranking, so if you want to be found for “shoe,” it’s a good idea to fit “shoe” into your domain name. One way to do this is to use your brand name along with a keyword term. So MillerShoe tends to work better than FantasticShoe.com. (Which is why MillerShoe is taken, but FantasticShoe is still available.)
Shopping Cart Life Span: How soon does your shopping cart expire for anonymous users? More than a few shopping systems use Session variables for tracking cart items, and expire within hours, especially for users behind prozies that change IP addresses often, thus rendering the current Session invalid (think AOL). Several studies point to the fact that customers will wait as long as 4 days before deciding to buy, and if the item they were looking at is still in their shopping cart, you just saved them several steps and increased the possibility of conversion substantially.
With time, you might consider using an affiliate marketing program, in which other sites get paid a percentage of each sale they send you. But it’s questionable whether a brand new site will benefit from an affiliate program. Although some new sites have profited, many new sites has yet to build the name recognition that makes using affiliates profitable.