The 'hijack' of the marketing campaigns began when mobile company 'O2' offered its Twitter followers free pizzas delivered to their office.
All people had to do was reply to O2's message with their location and a hashtag, and a handful of lucky winners would get their hands on the pizza.
Dan May decided to give it a go but the promised pizza never arrived.
Disappointed, he Tweeted O2 again, threatening to switch to rival phone provider 'Three' unless they made good on their pizza promise.
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Not to be outdone, O2 went for the nuclear option -- offering May free pizza for the rest of the year, the Independent reported.
His pitting of the two mobile giants against each other was well-timed with a deal to merge Three and O2, which came after Hong Kong telecoms conglomerate Hutchison agreed to buy O2 from Telefonica for 10.5 billion pounds, will go before European competition watchdogs next month.
But till then they were rival firms.