ForumsInternet/eCommerce

According to D&B, all 173 toy retailers in their database that have an on-line presence are linked to brick-and-mortar stores. Likewise, the Toy Industry Association does not include any members with on-line only operations. So it may be hard to find good industry data on which to base your projected financials. If you have a specialty niche of some kind, it might be easier to come up with something for that (but you didn't indicate it in your post).

You mention that your market "is virtually everywhere in the U.S." The D&B report notes that there are about 60 million children in the U.S. The number of toy buying households is steadily shrinking, and the amount spent per child is holding steady at best (about $415 a year). Contrast that with over 700 million children in India and China where the amount spent per child on toys is $34 a year. To paraphrase one D&B analyst, "Retailers in the toy industry may have to attract the attention of children around the world if they hope to sustain growth." I don't know if you wanted to think that big or not, but a global marketing strategy seems to offer a lot of potential opportunity for an emerging on-line seller.

Anyway, to answer your question, I would develop your complete marketing plan first, calculate your unit costs and margins, and then do PRO (pessimistic, realistic, optimistic) estimates on response rates, conversions, returns, etc. based on a cross-section of Internet retailers that have utilized the same marketing approaches you intend to use. It may not be simple or elegant, but at least it would confirm if you're in "this could definitely work" or "uh oh" territory.

Hope that helps. Welcome to the community and best wishes.