More and more of our daily computer tasks are moving to the internet. Few years ago i used to have a small software for anything: to tell me the weather, to read books, a calendar software, time tracking software. Now, i use all of them online, calendars, time trackers, document editing.
The bad intended persons may lose interest of trying to get into my computer to show me how i can take advantage of the 500$ antivirus which real cost is 1000$. Now the juice is online. The benefit of getting and placing his offer without approval on a website with decent traffic is similar with infecting hundred of thousands of computers. They upload a code and all visitors will see their offer. They are selling crap that will make you more harm, but since they don't put any effort in promoting the product they don't care. There are the threats that we face day by day. Fortunately the big sites that we visit each day are well protected, they have stuff that keep track of suspicious activity, etc.
2 years ago i installed wordpress to show some articles here, on IPGP.net . I forgot about it, and one day i noticed that i stopped getting traffic from google search engine. I investigated the problem and i saw that someone that used some automated software that exploited my wordpress outdated installation, inserted 20-30 hidden links into my blog pages just to get some google rankings. Probably he got none, because i bet google don't care too much about hidden links, but my site was kicked out of google search engine. I fixed the problem, i updated the software and then slowly my google rankings got back.
These types of attacks will be seen more often from now on, it is a pain, but we must pay more attention to this, update the software so the automated tools created will not work anymore.