What is up with these internet ads that are promoting free stuff for
participating in surveys?  What strings are attached?  More
specifically, I'm refering to the
eMarket Research Group webpage. 
http://www.emarketresearchgroup.com

The catch is that it is not a online survey site at all. In order to
get your free gift, you have to complete 6 sponsor offers.

From their Teems:

"A.10) Incentive Gift Redemption Requirements: To receive the
incentive gift for the promotion ('Incentive Gift') you must complete
all of following requirements:

(a) Submit your zip code to determine geographic eligibility (if requested) 

(b) Submit an email address owned by you that is valid and deliverable 

(c) Submit your accurate contact and demographic information such as
your mailing address and phone number

(d) Complete a total of 6 sponsor offers. To 'Complete' an offer, you
must sign up, get approved for and activate (where applicable*) the
sponsor offer, while following any instructions and terms that are
provided. Additional terms and conditions may apply to participation
in select marketing offers. You should read the terms of each offer as
provided by the our web site and the sponsor web site for an
explanation of these terms where they exist.

* For Discover Card offers, the card must be activated by making a
purchase, balance transfer or cash advance in order for the offer to
be considered 'completed'.


(e) Remain an active member for the duration of the time it takes the
sponsors of all the offers you've completed to report back to us of
your successful completion of their offer. Typically, it takes offer
sponsors up to 8 weeks (but ususally 4 - 6 weeks) to report to us that
you have completed their offer.

(f) Complete and submit an address confirmation/gift redemption
mail-in voucher form within 90 days of the original date of your
member registration.

These conditions above are mandatory for a member to receive their
gift. Once you have completed all the requirements above, we will ship
the gift to your mailing address. Please allow around 4 - 6 weeks for
shipping.

These requirements above are specific to the promotion ('Incentive
Gift') as chosen by you during registration. If you were to choose a
different incentive gift, the offer competion requirements as
described above are subject to change."

by completing these offers, they get paid as an affiliate and then
give you your gift from the money they made.

Legitimate online survey companies will not force you to sign up for
offers in order to get a gift.

An acquaintance of mine found that upon completing an online survey
(don't know which company it was), his computer suddenly started
trying to dial out and give information on his surfing habits.

More generally, online survey sites usually get revenues from your
answers in two different ways:
- the survey has been started as a request of one of their customers.
For instance, before investing in a new product line I may want to
find out if there are potential customers and needs for that new
product line. I go to a survey agency that does the survey for me.
This kind of customized survey is quite expensive, starting at let's
say $10k
- the survey is done to build a fully-qualified database on a given
field. For instance, the survey agency will ask you if you plan to buy
a car in the next 6 months. They can then sell the database exactly as
they would sell an "off the shelf" product. Car manufacturers may want
to buy the database dealing with cars. They will get statistics and
possibly contacts. Those databases are less expensive, usually a few
cents or bucks per record, depending on how precise and unique the
database is.

Hope this helped and sorry for my English!

LCT