A little due diligence would save people a lot of money and headaches. This is a scam wrapped up in partial truths and glowing promises. Yes, mature blueberry shrubs/trees (6' to 12' tall) can produce such daily quantities
but the omitted qualifier is "during their fruiting season and given the right climate, water, sunlight, nutrients and protection."
You should never buy via mail order unless you are at least vaguely familiar with the topic
and the supplier. In this case:
a) do you know if YOUR particular Plant Hardiness Zone is suitable for blueberry growing? -
http://www.usna.usda.gov/Hardzone/ushzmap.html
b) do you know YOUR particular microclimate and soil conditions? (I mean, you DO know what your soil pH is as well as what pH blueberries require, and their moisture and nutrient requirements, right?)
c) have you considered the space constraints of YOUR particular garden to avoid neighboring plants from competing for nutrients, water, light and space?
d) do you know the name and reputation of the supplier.... not the spammer?
I would urge you to turn to your local Cooperative Extension Service or Master Gardener's Hotline where you can obtain free factsheets on vegetable and fruit gardening, or at the very least, Google for reputable information sites, i.e. -
http://plants.usda.gov/java/profile?symbol=VACO
Successful fruit and veggie gardeners know that it costs time and sweat to maximize results and prevent disease and pests and lack of nutrients from ruining harvest results. With something as delicate as blueberries, you'll need to do quite a bit before ever shelling out money for plants, incl. deciding how to protect the plants from pests (birds, deer, etc).
FYI - home gardeners rarely get many if any blueberries, even if the plants survive. Best chance of success comes from erecting a permanent enclosure of tall posts and netting/metal fencing big enough to walk around in, large enough for the mature highbush blueberry trees. (remember, they grow up to 12' tall) Sure, you can prune blueberry shrubs, but do you know when to prune and how, so you're not lopping off the parts of the plant where the flowers and fruits will form?
You'll also need patience - the tiny plants you'll receive can take YEARS to mature.
There's NOTHING special about the spammer's plants, as one web site linked to this spam eventually admits in a FAQ:
"They are not hybrids. They are Vaccinium Corymbosum - the Highbush Blueberry"
You should only buy mail order plants (any plant) from a REPUTABLE mail order nursery. There are several great online resources that maintain lists of reputable growers. This is one of my favs:
http://davesgarden.com/products/gwd/
Another caveat... NEVER buy ANYTHING from an unsolicited email, especially if they're full of rosy claims and untraceable testimonials. Period. In this case of spam, a simple check showed the sender was actually a day old domain name hosted in BUCHAREST ROMANIA! Steer clear.