Oyster Card

Why is Transport for London and and third party websites promoting the Oyster pay-as-you-go card for tourist? I think it is great and I have one. But as a pay as you go card I think that it is better for people working and commuting in London. The Travel Card is much better for tourist as it can be used for select period without the owner having to think about the value on the card. Yes, it can be placed on an Oyster Card as well as a buss pass, but this is rarely made clear by other writers. The Travel Card was made for visitors and works well. The fact that it can be used on an Oyster makes it better but some writers have made this very confusing. Or is it just me? I do know about the Visitor Pass and some of the others but the TRAVEL CARD should be explained clearly to incoming visitors. Yes yes, yes, I am aware that some visitors can save money if they know how little they will be using system but I think they are a rare breed. With a one day, three day and seven day card I think any combination will fit the needs of visitors. I am open to feedback on this but my rant is that the pay card is promoted too much over the Travel Card, which is downplayed. But, maybe it's me. I am often told so by so many.