| Personally the deal for 12 months is too good for any
| Photoshop/Lightroom user to turn down. Whatever happens they will still
| have their older copy of CS which qualifies them for the deal.
The whole point of such marketing is to get you hooked.
They hope you won't be willing to go back to the old version
after the deal is over. Meanwhile, if you found the added cost
of $10/month worthwhile then you must already think the
rental version is notably better than CS6, which implies that
they can probably get away with a price increase at year's
end, because you'll be loathe to return to CS6 by then.
It's like cable TV promos that promise "only $xx
for 6 months" without telling you the real price. Anyone
who's not prone to lying to themselves will find out
what the real price actually is and decide whether
they want the product at *that* price.
(Salesmen rarely cheat outright. They just help one to
lie to oneself.)