Increasing the tax rate isn't what matters; the structure needs reform. For example getting rid of income tax and replacing it with revenue taxes, which are more difficult to circumvent.
That just benefits vertical integration. Amazon would pay less taxes in Amazon basics than third party goods. What you really want is a VAT. You're only taxed on the value add of your product. It's widely regarded as the most efficient tax and the US is one of the only countries that doesn't use it.
VAT does capture B2B transactions. That's what makes it different from a sales tax. I'm pretty sure that you already have to pay VAT when buying online ads.
Is it? In the US, at least, sales tax is taken on top of listed prices (it's uncommon for an establishment to list "tax included" prices), so essentially a customer is paying for the product and then paying the government on top of it.
Unless your thought is that businesses would charge more if there was no sales tax. I don't really buy that, though; businesses list pre-tax prices specifically to avoid sticker shock.
Intentionally so, because taxing B2B revenue is effectively a financial penalty for not being a huge vertically-integrated megacorp. It means that any goods which have more than one company involved in their production are taxed at a higher rate than ones where every step is done in-house. This is not generally a desirable tax incentive.
