Using bitcoin on online payments is nice idea because it will help you to pay your bills or payment in some easy steps. In addition to that,  as of now there are lot of online sites who already start to accept bitcoin and I think it will help them to gain more funds.

Soon, but not in bitcoin i think. Google is a huge company. They might create their own coin and will be use to all of their services. And other companies will do that too. I think that will be the future of cryptocurrency and bitcoin will be the center of it.

If every company starts coming up with their own form of cryptocurrency how do you give a valuation ,the concept of bitcoin is decentralization and that is the reason it is successful and for big corporates to accept bitcoin it might take a longer time,because if they look at the financial structure it may not be a viable solution for them to start using bitcoin as a payment system until they have a solid front end,hope we will see them in the future.

Bitcoin as payment for youtube and other websites?.
It is not impossible, but I think not everyone wants Bitcoin as their payment to received online. Bitcoin can be included in the option of mode of payment like Cash : Bitcoin : Fund Transfer and the like. Some doesn’t want Bitcoin because we all know that Bitcoin is a cryptocurrency and the value of interest in unstable. If the value increases then its good but if it decreases its totally a loss. They tend to choose payment through cash because you have it already in your hands. But if you do not need to use it right away its better to make payment as Bitcoin where you can make it as an investment. Maybe in a few more years Bitcoin will be included in the option of mode of payment. 😊

soon. probably when bitcoin recognize as a currency countries such as America, China, UK. Then such sites will have no choice but to make such services possible

Though bitcoin is already recognized by most countries as alternative payment for products or services, they still are reluctant on making bitcoin as payment due to its decentralized nature. But by basing it from the charts, bitcoin has shown tremendous price increases over the past weeks and I guess that big organizations/companies will start to utilize it. At the end of the day, money is everything for those businesses and making bitcoin as payment will garner them more profits compared to fiat. Lastly, the only hindrance that barriers this idea is the availability and acceptance of people into bitcoin.

Youtube is owned by Google and being under there program is really hard to see for it to accept Bitcoin as one of their methods to pay their advertisers. Google is a known company that moderates and enforces law in their websites, such as Youtube blocking and deleting videos that have copyright infringement on them and also disabling some monetization on certain videos that have violated some of their rules. With that being said it will be a long time for Google to consider paying their advertisers with Bitcoin.

I don't think Google will ever adopt Bitcoin as their official currency to pay for their services. If they ever want to adopt crypto as a payment, they will surely like to make their own crypto-currency or tokens. Other sites except those are related to crypto-world, don't want pay in BTC coz of its price fluctuation.

Bitcoin payments only take a few seconds and most transfers are confirmed immediately.this is the main advantage