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Comment The how and why (Score 3, Informative) 176

first of all let me pretext all this with the fact I have been working in online advertising for about 5 years for a caouple of major publishers and now an agency side adserving company. The industry as a whole has a glut of technical knowledge and is mostly sales driven. Calls to adservers usually use a call to an external javascript file which is dynamically generated by the adserver. When this call is made it passes along some variables to let the adserver know how that position is targeted. At this time some tracking also happens, so the system will count an impression against a certain ad. For this reason caching can't be done - the system has to record and decide which ad to return on the fly to make sure delivery is correct and possibly even do some optimizations around which ad to show. Think of it as a giant decision engine which also collects data and uses that to decide what to serve next. There is another way to call in an ad, and that is to use Iframes, unfortunately these will point at a different domain so it isn't possible to resize or do anything outside the box, unless the ad being served is a rich media provider who are allowed to have another little html page on the site's domain they can call up and then use to write back to the main page. Because of all the different types of javascript that can be served back depending on the company providing the ad, the ad has to be put in place if using javascript as it will often look at where in the DOM the script is called. There are too many providers doing different things, and the only way to make things work is to call it straight in.

Comment Re:I suppose the opposite motivation exists but .. (Score 1) 176

Sorry, but it's not possible with some of the ad formats being used. I actually have looked in to this and have set up some sites so the ads do load last, this unfortunately is a fair bit of work for the publisher not only initially but also going forward and most online advertising companies do not have the technical expertise - they are primarily sales focused institutions. It also means that they lose flexibility in what they can serve and as such may lose out on money to other websites that can do what a client wants.

Comment Re:Ad Caching? (Score 2, Interesting) 176

actually the most important thing is not showing the ads, but counting the ads shown. I did work at a company that had a fallback where if there was a bottleneck it would switch to serving a default ad - but that makes no money. Clients pay on the number of views/clicks an ad gets and you have to have the request go through to the server to get this. Also the adserver needs to decide what ads to show. It might be acceptable for click only ads - but it's the view based ads that make the most money, and you would get rid of any possibility of optimizing delivery of those ads - i.e. less money.

Comment Re:Load the ads last (Score 1) 176

actually it is difficult. The ads that get served to a page are usually more complex than the content on the page - they can call in javascripts that call in more javascripts that put iframes within iframes to expand on domains etc etc etc. If the ads wree all the same format then it would be a cinch to load up the ads at the end, but unfortunately due to ads being served through other providers that use a richer set of javascript it can't be done.

Comment Re:No surprise (Score 1) 176

It depends on the site. Alot of sites make an external javascript call - the ad is returned as a javascript file and that is written on the page through document.write. Because it is javascript the browser has to wait for the file to come back before continuing to load the page. Other sites use Iframes to display the ad and so the content of that iframe is loaded up independantly and will not slow down the page, but this also means that ads loaded on to the page aren't as flexible. I believe the majority of sites/adservers use javascript calls

Comment Re:Idling corporations and working people (Score 1) 378

I doubt this - I don't see any intentions of CityRail trying to make money. In fact - I do agree with CityRail in this case. How many people will download the app - think it's official data and then complain to cityrail when they fail to check out their website for trackwork being done? I'm going to go against the grain here and actually say that while the app is useful, it does have the ability to cause more harm - especially if the user is on an iphone and just check the website for train times. you'll also find the rail system is not privatised (yet) - so making money isn't part of their scheme.

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