I don't think it necessarily means it's a scam, far from it in fact, but I must admit I like to see the progress of a sale too. Problem is that even if they do show sales, how do you know those figures are accurate? They could just be making up figures to attract investors. There can be any number of reasons as to why a project doesn't publicly display the figures. I find that a better way - sometimes - is to look at the address you're being asked to send the money to, can then see look to see how much money has been sent to that same address, and how many individual transactions.