it is always good for the businesses to advertise if they have a bitcoin payment but currently if i want to find an online store that accepts bitcoin i usually use google with keywords containing "bitcoin" and "the goods that i want to buy" and i find these stores, not all of them are good though.
Explain what you mean by that. Not all of them have the product you're looking for or are they deficient in some other way?
i am mostly talking about the trust! many of these online shops accepting bitcoin are brand new businesses so it is hard to trust them especially because of the one-way nature of the bitcoin transactions.
i remember a while back i wanted to buy a game online with bitcoin i only found one established site with some small amount of good reputation the rest were unknown brand new sites with interesting prices but zero trust.
but also the other part about "not all of them having the product i want" is also true.
also "not all the shops have bitcoin payment option" hence the first line. for example i want to buy domain/hosting from godaddy but they refuse to accept bitcoin ;(