What is the best bitcoin business to create that will grow throughout 2017?
I think that it is better for those huge companies that are already on the market to add the bitcoin payment method to their website and allow their clients/users to make payment with bitcoins.
it's always be the first goal , make bitcoin accepted in a lot of merchants especially a huge companies like ebay and amazon maybe? once they accept bitcoin i believe there would be a big impact. but while waiting that's happen , you can always create a business that most peopple looking for. you can create an alternative market as a replacement of what people want on ebay etc.
I think there is already a service like this to buy in amazon and even now(or very soon) on ebay but at the end the buyer should pay some fees which increases the expenses to buy something where he can easily buy with paypal or cash cheaper, but an unique market depended from amazon/ebay needs time and large community.