Hi cross country I did some looking around and it appears to have been called many different names over the years. Sadly it is a scam. Something like this:
A lot of companies will say you are entered in a contest and then write to let you know that your poem was "specially chosen" to be published in a book, that they will then try to sell you with a hefty price.
They don't say that they are putting the poems of every single contest entry into the book. Most (unknowing) writers will buy a copy for themselves and some will buy for family & friends also. Avg 500-? poems a book, at $40-50 + s&h a pop. Nice chunk of money. They offer leather bound/embossed ones too for much more. The poetry market is rife with scammers. If someone wants your poem in a book, it's because it's good...not because they want your money.