As i work for a similar online company, i know what they do with the data.

You must know we're going to ask the inevitable now....what do they do with this data? :)

Most companies don't sell your personal data (some do, read the terms) but what they do is they sell the data and all of your purchasing habits without your unique identifying information, e.g. your name, surname or last part of your postcode.

However, this profiling that is sold, which including all of your buying habits is cross referenced with other database where it is possible to match purchasing habits to an individuals all the way down to a street level.

All you need these days is a first name, email address and/or ip address.

Eventually to get enough pieces of the jigsaw to get an exact match.

We recently had a meeting with callcredit.co.uk - They used to run finance databases, setup in the 80's. Collecting personal details and today they pull in data from several sources to give you a true picture of someone's buying habits : http://www.callcredit.co.uk/products-and-services/consumer-marketing-data-and-segmentation/local-area-data-and-demographics

E.g. They presented to us - we have a modest email database of 5 million people of which they can tie an email address and first name to their comprehensive database of buying habits. They can typically tell us family A goes on holiday twice a year to southern europe, lives in south london, is of higher than average household income, drives a volvo, has 3 children, shops at Tesco, buys their furniture from ikea, has a tesco credit card, watches predominantly bbc1 and channel 4 and likes to use discount voucher web sites. Their mortgage is between x and y and is renewed in December.

The profiling and matching is scary.

Most of it we don't even realise, like those questions the bank clerks ask us like do you have a mortgage and when is it renewed.

We work closely with a company selling life insurance. He pays his staff based on who gets through to the customer on the phone first after the customer submits a web form.

Essentially your purchasing habits are bundled into a profile and sold on the open market. You internet traffic data is sold by your ISP to hitwise, your credit score is sold by experian to lenders and your supermarkets lur you into loyalty schemes which profile your brand loyalty and even go 1 step further and give you credit cards that your can earn points with so they can upsell to you in a vertical market.

Essentially all this means is, the big companies know what you buy, when you buy it and can therefore market to you more effectively. Especially in finance. A lead is worth £100 and to buy that lead more effectivly makes a massive difference. E.g. if you know when someone's car insurance is due for renewal you can start to market to them in advance or if Tesco know you have 2 children even if you buy nappies and a peppa pig soft toy they will send you vouchers for the Sea Life centre and you then become a sea life centre customer and sea life actually pay for this lead. Because you are likely to go back at some point and give them incremental business.