Are you guys remitting sales tax in every state you sell a product?

I am looking to sell a bundle of PDFs on my website, but from what I can tell I would have to register with the department of revenue in each state I sell to in order to remit my sales tax because Squarespace doesn't handle this on their end. Those of you doing ecommerce through your website, is this really the system? Do you have to file sales tax in every state? Or am I missing something?

I am by no means a tax expert but I believe that in many states, if you are shipping goods from a business located in another state, you don't need to start collecting (and paying yourself) sales tax until you cross a certain threshold of sales annually in that particular state. Have heard that the $ amount varies by state. Good question for your cpa!