When you upgrade your mobile phone contract, you look for the best combination of free minutes and texts that you can get, together with a free phone that takes your fancy.
With mobile broadband you're after the equivalent in gigabytes of data transfer, and to tempt you companies are giving away a limited choice of free laptops.
Of course, none of the notebooks offered with mobile broadband tariffs are truly free. The costs are factored into 18-month or two-year fixed contracts. If the notebooks - which are usually bought from China or Taiwan in huge batches - cost the companies between £100 and £200 each, paying just £25 for 24 months can still leave up to £500 for the broadband providers' pockets.
Free notebooks were first tested as an incentive to taking out a mobile broadband contract at the beginning of this year, when PC World offered an Advent laptop with an 18-month '3' contract for £35 a month.
That trial deal proved very popular, and there are now similar free laptop offerings from several other companies. This type of contract has fast become an effective way of shifting both notebooks and mobile broadband.
At the time of writing, PC World is repeating its deal, offering a free Dell Inspiron 1720 - normally £399 - for £35 per month with a two-year mobile broadband contract. This is now just one among a host of 'free laptop' offers.
The Carphone Warehouse offers a similar range of laptops, but it has taken a rather different approach at the low end by offering a custom-made subnotebook with its twoyear, £25 per month Orange deal.
The Webbook is made for the company by Elonex and sits halfway between a typical laptop and an Eee-style netbook.
The idea that somebody who wants mobile broadband might want a sub-notebook is a sound one. Most people want Internet on the move for email and web news rather than gaming or video, so something small and light with better functionality than a PDA can be appealing.
So how good are these bundle deals? If you take up a mobile broadband contract based on connection and a USB modem alone and then buy a discounted notebook, do you get a better deal? We did a bit of research using respected Internet sources, and here's an example of the results.
Please note this is only an example of the trends; these offers appear to change weekly - if not more often.
When checked, T-Mobile was charging £15 for 3GB per month over 24 months. You could combine that with the Axses E15 laptop from Novatech, which has a dual-core Pentium T2370, 15.4in screen, 2GB memory and a 160GB hard drive.
It runs Vista Home Premium and costs £298, so the whole deal comes to £658. At the same time, PC World was hawking a 5GB-per-month, two-year contract with T-Mobile for £30, with the choice of a selection of laptops with selling prices up to £350.
The best on their site on the day we conducted our research was an Advent dual-core Pentium T2390 with, again, 2GB memory, 160GB hard drive and Vista Home Premium OS.
The cost for this over two years would be £720. Given that the PC World deal offered two-thirds more data per month for £60 extra over two years, it did represent the better deal in our comparison - but not by much.
The fluidity of these deals means that as soon as you've chosen one it'll be out of date anyway; the mobile broadband market is in a state of flux right now.
The choice isn't whether to plump for a free laptop. The choice is whether the cost of mobile broadband - and the extreme length of contract that comes with free laptop deals - is really justifiable to you.
First published in PC Plus magazine