Exactly, competitors may well be the source of your problems. It's cheaper (and safer) to trash your competitors than raising your own rankings (with SEO).
When I ran a torrent tracker for TV shows I was pushing $1m+ a year through PayPal. I had my own personal account rep, etc. They didn't give a fuck about the pirated material.
My competitor though, they would email PayPal every week telling them we were selling child porn. It would take PayPal no time to lock our account while they logged into the tracker and looked around to check it was still only TV shows. We'd be out of revenue for a few days each time.
That trick is absolutely the quickest way to destroy any online business.
When I was in e-commerce, I was told a story that implied that one merchant in a niche market paid a botnet to DDoS his competitors in the tiny niche during the Christmas rush.
I have no first hand knowledge if it is true, or who the merchant was, or the botnet, it's all hearsay and rumor ... but it's the sort of rumor you have no trouble believing after working in e-commerce for a few years.
With something like coupons where you are making affiliate revenue, advertisers have it pretty well dialed in how much they can bid and still make a profit. Since they aren't selling a product directly, there is zero advantage to continue bidding if the price goes up. They are left with two options: find a new market, or push out bidders to low the competitiveness of the market.
My competitor though, they would email PayPal every week telling them we were selling child porn. It would take PayPal no time to lock our account while they logged into the tracker and looked around to check it was still only TV shows. We'd be out of revenue for a few days each time.
That trick is absolutely the quickest way to destroy any online business.