What: Shares of Constant Contact Inc (NASDAQ:CTCT) rose 22.2% early Monday after Endurance International Group Holdings (NASDAQ:EIGI) announced an agreement to acquire the online marketing specialist.

So what: Endurance will acquire Constant Contact for roughly $1.1 billion, or $32 per share in cash, to be funded with fully committed debt financing. This values the company at roughly 12 times adjusted EBITDA and represents a 23% premium over Constant Contact's closing price on Friday, October 30, 2015.

"Our team has always been passionate about helping small businesses do more business," explained Constant Contact CEO Gail Goodman. "Joining the Endurance family of brands will allow us to extend our reach and be a better partner to mall businesses across the globe."

Now what: This move isn't terribly surprising, as Constant Contact and Endurance are well aware of their synergy potential. The two companies most recently rolled out a strategic partnership in May, for example, that helped bring a significant number of new email service customers to Constant Contact.

That was a step in the right direction for Constant Contact as it coped with slowing growth, but it wasn't enough to help the company avoid reducing its full-year outlook for the second time in as many quarters in July. Keep in mind that even after today's pop, shares of Constant Contact still sit around 13% lower than they started the year, and the deal still requires the approval of Constant Contact shareholders to proceed.

Nonetheless, according to Endurance's press release, the transaction is expected to close in the first quarter of 2016. With shares now trading within pennies of the proposed acquisition price, I think Constant Contact shareholders would be wise to take their quick profits off the table and put them to work elsewhere.

Steve Symington has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.