The reason to say no to a potential acquirer is that you believe you’ll be valued significantly more later on, and to make good on that belief you have to grow quickly. In April, Crashlytics, the Boston-based mobile crash reporting company, told us they’d received an offer for acquisition and turned it down. Instead, today the company announced it had made an acquisition of its own.

We learned last night that Crashlytics has acquired FireTowerApp.com, which helps users find javascript errors on theirs sites, as a means to furthering its mobile web strategy. FireTowerApp is led by Aaron White, a Boundless Learning co-founder, but the acquisition is of the technology itself. However, Wayne Chang, Crashlytics’ co-founder, said the FireTowerApp team remains involved in its development.

“We see the space being consolidated,” Chang, Crashlytics co-founder, told me. He also said another competitor was nearing a deal to itself acquire FireTowerApp.com before Crashlytics snuck in at the eleventh hour.

No financial information was disclosed. In April Crashlytics raised $5 million in an oversubscribed A round.